CardShark BidBase
Practice Program
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Contents:


Related Help Files:




Reading through this whole manual before trying the program is not essential, but if you want to try something that requires clicking on several menu items, it's a good idea to at least read about those menu items.

In particular, the Conventions menu functions should not be attempted before reading this documentation first.



Introduction

Deals made by the Practice program are randomly generated. The number shown for each deal is used to seed the computer's random number generator which allows you to display any deal you've seen before by entering its deal number.

Here are the main functions of the BidBase Practice program:

  • Get random deals to practice bidding against BB.  
  • Practice bidding conventions already set up by BB or enter your own auctions to practice. 
  • Download PBN files (tournament deal records) and bid or watch BB bid selected deals. 
  • Manually enter deals to bid or to see how BB bids them. 
  • Generate lists of deals for practicing specific conventions. Many of these have already been created for immediate practice either in BidBase or on Web pages .
Here are features which can be used when practicing bidding:
  • BB tells you if your bid doesn't match the database. 
  • Rebid with analysis to see why BB's bid wasn't the same as yours.  
  • If you disagree with a BB bid you can edit the database entry which resulted in the bid using the BidBase Editor. 
  • Show Double Dummy Analysis and other statistics for each deal to see the maximum result for each position. (See the screen shot above.) 
  • Review deals by scrolling back and forth through the deal numbers or by entering a specific deal number. 
  • Mix up cards for 2-3 players while keeping your own to see how the bidding or DDA might differ.

Tip: If you only have one hand in a deal and want to see how BB bids it, use BidBase Editor's Enter Hands function, or you can use the Enter Hands function in this program to enter one hand and have the program randomly deal the remaining cards to the other hands.

BidBase Practice program is intended primarily for practicing bidding conventions. The BidBase Editor allows users to enter any kind of convention or other bids they want by just filling in boxes with the point and distribution requirements for the bids.

Because there is a virtually infinite number of possible bidding sequences, it is not feasible to have database entries for every possible bid. If BidBase does not have a bid for a particular situation, it will return a Pass.

If Options - 11-Deal Average DDA is turned on, BidBase can compute bids based on the DDA optimum contracts.

You can also add bids to BidBase as you play. See Save Bids below.


Practice Random Deals:

The basic use of the BB Practice program is to have it display one random deal after another with which the user can practice bidding. 

Several ways are available for practicing:

  • Click a bid in the Bid Box for any or all players. BB will tell you if your bid differs from BB's.
  • Hide all the hands but south and bid for south. Click BB Bid when you're ready for BB to bid hand.
  • Un-hide all the hands and just click BB Bid for BB to make each bid.

Dealing: BB does not use manually created deals. Instead if you start with deal 1 and practice each deal in numerical order, BB will seed the computer's random number generator ("RNG") with each number, such as 1, 2, 3, etc., to generate each different deal. This allows BB to create a virtually unlimited number of random deals.  
Every time the RNG is seeded with the same number, it will display the same deal. Say that you practice deals 1-10 and want to see the third deal again; you can enter deal number 3 and BB will seed the RNG with 3 and the deal will be displayed again.

Bidding: BB can bid a couple of rounds of non-conventional bidding, but the real advantage of BidBase is that any auctions or conventions can be entered into the database and BB should contain all rounds of bidding which are specific to each convention. 
Image Let's say that north opens 1, east passes, and south makes a Splinter bid of 4. That is the end of the bidding specific to Splinter bids. The player should know what to bid once partner has shown 13-15 points and that he has 4+ trump support and a singleton or void in the suit bid.

Very few entries in BB have specifications for an actual call of Pass. Instead, most of the time when BB makes a call of Pass, it is because no entries were found matching the specifications of the given hand. When this happens, you will usually click the right arrow button to go to the next deal.  
Alternatively, you can click on a bid in the Bid Box and BB will ask if you want to add that bid to BidBase. This is the easiest way to add a bid, but a more effective way is as follows: 
If you disagree with BB's bid when practicing in this program, you can click the Edit Bid button, review the specifications in the entry which resulted in BB's bid, and if you wish, change those specifications or create another entry with different specs to supercede the entry BB used.

Obviously, whichever conventions you want to practice have to be activated on the grids in the BidBase Editor and they should not have the same bids for different conventions which are activated. For example, make sure that both regular Blackwood and Roman Key Card Blackwood are not both activated; if they are, the first will be used. 
If more than one entry for an auction...
matches the specifications for a hand...
the first of the matching entries will be used.  
Bid entries are tried in Bid Order Number sequence.
All standard bids (not conventions) have Bid Order Numbers of 900000 and up (the Order column)...
All conventions have BONs below 900000...
As a result, when a convention is activated...
it is used without having to deactivate the standard bids which come after it.
When the convention is deactivated, the standard bids automatically come back into use.

In the image above, the Sel column is blank if the convention is Selected/activated.
The Sub-convention (such as Splinter in Bergen Raise: Splinter) is blank if activated.
The Pct column lets individual entries be de-/activated.


Practice Bidding Conventions

BidBase lets you practice for or against specific conventions. The biggest problem with playing a lot of different conventions is that most of them don't come up very often, but are very helpful when they do -- IF you and your partner remember them.  
Practicing your conventions once a week or so would not take that long and would keep them fresh in your mind. Or if you are going to play with a partner who uses one or more conventions which your other partners don't use, practice those conventions before playing with that partner.

Bidding Quizzes let you practice bidding conventions by generating random deals until it finds one whose starting bids match one of the auctions specified. It displays the hand and lets you make the next bid, then it has to continue the search for another matching deal.

If this were the actual process, it would mean that you take a short time to make each bid followed by a long time of BidBase searching for the next deal. To find 100 deals matching the Jacoby 2NT auctions shown, BB had to go through over 6000 deals.

So that you don't have to sit through that, BidBase does the searching through thousands of deals while you check your email or go for coffee or take a nap, then when you practice, it can present each deal number in turn from the file instantly instead of having to search for a matching deal after every question while you wait.

The following are the instructions for the menu items in the Conventions menu. You can start with Step 3 to see a list of conventions for which quiz files have already been made, but it isn't that hard to make quiz files of your own with which to practice. 
(1) Read these instructions. Right. You're already doing that. We just list it anyway so that these step numbers will match the Convention menu.  Image
(2) Create convention files. These are short files, stored in the PracticeDeals directory, which only contain the auctions which the bidding for a deal must match. An example is shown at the bottom of the screen shot. The player will make the next bid to practice the convention. As you can see, this is a very fast and simple step. 
In BidBase, the auction to which an entry's bid applies is called the "Prior Bids". So if you enter an auction like 1S-P-2N-P, those would be the Prior Bids for entries which make the bids responding to that auction.
(3) Find matching deals. Clicking this menu option causes BidBase to generate a series of random deals, looking for ones whose bidding matches the specified auctions and recording the deal numbers and declarer's position of matching deals to a file with the convention's name.  
These files are in the PracticeDeals\Deals directory, each using the convention name as the file name with an extension of ".Deals". Because the .Deals files are in a format only the program can read, the same data in them are stored in a file with the same convention name but an extension of ".txt". These can be viewed with any text editor.  
The first line in the file contains the number of deals in the files and the last deal practiced. The rest of the lines contain the line number, the BidBase deal number, and the number of the dealer, where 1=south, 2=west, etc. 
When BB starts searching for matching deals, it may appear that nothing is happening. That is because each deal being tested is not displayed in order to make the search go much faster, but if you look at the deal number displayed to the right of the Deal button and the dealer displayed to the right of the Dealer button, you will see that they are changing.
(4) Practice the convention. This option shows the contents of the PracticeDeals directory. These are the names of each convention for which starting auctions have been entered. After selecting a convention, BidBase opens its .Deals file from Step 3.  
BidBase starts with the first deal recorded or, optionally, the next deal after the last one you practiced. It then makes the bidding for the deal to see if it matches one of the specified auctions.  
Because the BB database may change over time as improvements are made, the bidding for a very few deals may no longer match the specified auctions and thus not belong in the practice Deals files any more. In that case, BB will offer to delete the deal from the file. 
If a significant number of deals no longer meet the criteria, it may be more efficient to delete the existing file and redo the Find matching deals function to create a new Deals file. 
Bidding a practice deal doesn't have to stop with just your next bid. You can practice subsequent bids by clicking in the Bid Box. BB will tell you whether or not your bid matches the bid BB would have made. Or you can just think about what you would bid next and click BB Bid and let BB make the bid. 
You can continue bidding as long as you want, at which point you click the right arrow to move to the next matching deal.
Because each BB deal is created using the computer's random number generator, a virtually unlimited number of different deals can be created. A deal number is used to seed the random number generator which allows the same deal to be recreated by entering the same seed number.  
The advantages of this method as opposed to manually creating deals to match the requirements of a convention are:

  • The deals give a realistic variety of bids compared to made-up deals.
  • You can create practice files for any conventions or parts of conventions or, in fact, any sequence of bids you wish to enter and BB will generate random deals looking for those whose bidding match the specified auctions.. 
The auctions can be as long as needed to get to the point where you want to start practicing the bidding. The two auctions above are all that are needed for Jacoby 2NT. The player and BB would make the bids which come after that. If the player's bid does not match BB's, the program will alert the user.

More about creating auctions for conventions

The "x" Factor: Let's say that you wanted to practice defenses to 1N opened on your right, such as Meckwell. You could just enter one call - 1N - but then you would be shown every auction which starts with 1NT and in only a small percentage of them would 2nd chair have a hand suitable for bidding Meckwell. Wading through the rest of the deals would just be a big waste of time. 
To avoid all the 1N-P deals, an "x" can be added before the P, such as 1N-xP. This causes BB to skip any deals with bidding starting 1N-P. Since any non-passing bid after 1N would be Meckwell, this solution works fine... with one more modification:

The Barred Bid: The original, basic Bergen Raises consists of only 3 responses each to 1H-P and 1S-P. Those responses are 3 of the major, 3C, and 3D. But there a ton of other (non-Bergen) bids that could be made, and it would be very inefficient to try to "x" out each one of them to just get the deals suitable for Bergen bids. 
Image Instead, a vertical bar ("|") is put before the bids you do want in the auction for BB to match to the bidding for random deals, but you don't want the Bergen bids to show up as already having been bid, so the bar before the bid says to match the auction, but don't show the barred bid. Instead, leave it for the user to figure out. 
So BB will show a deal in which the bidding starts, say, 1H-P-3C, but all the user will see is 1H-P and it will be up to him to figure out what to bid next.

Now lets go back to the Meckwell auctions to fix another problem. While 1N-xP will, indeed, skip 1N-P deals, when it shows the bidding to the user, it will show the second bids, such as 1N-2C and ask you to make the next bid. What you want is for you to be the one to bid 2C. To avoid that problem, add a bar before the x, like 1N-|xP. 
Now BB will search for deals with bidding starting 1N followed by any call but Pass, but it will only show the 1N to you and ask what you would bid with the hand given.

If you want to practice responding to 1N when RHO makes any call but Pass, you would enter 1N-xP only this time you would not enter a "|" before the "x". This will cause any 1N-D or 1N-2C, etc., to be shown except 1N-P because a deal starting with that would have been skipped. For all other bids by RHO, you get to bid in 3rd position.

Accept any bid: To tell BB to accept any call a player makes, enter "A", such as 1N-A. This lets you practice all responses to 1N no matter what RHO does; however, this opens up a large number of different bids and conventions. Since Stayman and Jacoby Transfers shouldn't require much practice, it would be more practical to restrict the auctions to less common conventions, such as. 

      1N-P-|3C
      1N-P-|3D
      1N-P-|3H
      1N-P-|3S
      1N-P-|4N
      1N-P-|4C
 Nevertheless, there may be times when "A" can come in handy.

All of this may seem a little confusing just reading about it here, but a number of conventions already have auction and Deals files for them, and you can try them to see how all this works.

To summarize:

  • Auctions must start with the first bid. A convention which might come up only after a variety of opening bids cannot be quizzed, except for ace-asking and control bidding, to be discussed later.
  • An "x" says to skip an auction which has the x-bid in it, such as 1N-xP.
  • An "|" says that the auction must contain the bids after the |, but that those bids should not be displayed to the user.
  • An "A" says to accept All calls at that spot in the auction, such as "2C-A" where opener's partner must respond over any call by RHO.
 Pretty simple, eh? Well, there's...

Even more about entering auctions:

Image Long auctions are okay as long as there is not such a variety of bids in them to make the number of possible auctions overly long. 
For example, the auctions for New Minor Forcing are somewhat lengthy, but there's not much purpose in practicing any of the earlier bids because they are pretty simple. This illustrates that your specified auctions should go up to the point where you have to make the main decision about what to bid next.

The auctions you enter (and bidding answers) must be in the BB database. See the BidBase Editor for more information. In other words, if you and your partner have a convention which only the two of you play, the entries for it will not be in BidBase so a quiz can't be made for it (unless you add the entries or get us to do so).

The convention you are practicing must be activated.

Required opening passes must be specified. For example, when practicing Drury, you must enter something like P-P-1S-P-2C because the 2C Drury bidder must be a passed hand and entering the starting passes is the only way to tell the BB Bidder that he is a passed hand.

When you are through entering an auction in the box above the list of auctions, press Enter to save it to the list.
To delete a line from the list, double-click on it.
To change an auction, single-click on it to copy it to the edit space above the list.
When you save the changes, it will be added as a new line. Double-click the original line to delete it.

Multiple specified auctions must always contain the same number of bids in order for the position of the quiz bidder to always be the same. 

The odds that a particular convention will come up

Since the Find Matching Deals function continues until 100 matching deals are found, the .txt file lets you see what the odds are of being able to use a particular convention. For example, the 100th matching deal in the Jacoby 2NT.txt file is (as this is written) deal #6096, or more than 60 deals to get 1 matching the Jacoby 2NT auction. 
But BB doesn't just test a deal using one dealer. If the bidding doesn't match when South is dealer, then BB retries bidding the same deal with West as dealer, then North, then East. Thus each deal is tested four different times. If BB tested each deal only using one dealer and then moving on to the next deal, it would take about 24,000 deals to get 100 matches, or 1 in 240. 
So if you are South and want to know the odds of your opening 1 and partner bidding 2N with the opponents passing, those odds are 1 in 240. If your club tournaments always had 27 boards in play, you would only get into Jacoby 2NT as declarer once in every 8.8 tournaments. or once in every 4.4 tournaments in which either you or your partner makes a Jacoby 2NT bid. 
If you only played once a week, you would only be playing the Jacoby 2NT convention once a month.

Ace @sking:

In BidBase, all Prior Bids plus the hand being bid are usually passed to the Bidder to use in looking up a bid. Normally each bid in an auction (Prior Bids) narrows down the list of different bidding entries which can legally respond to it. However, ace asking bids such as 1430 can be tacked on to virtually EVERY auction which could at least double the size of the database.  
So instead, ace asking convention auctions in BidBase start with just the bid which calls the convention using the format of 4N@## where the first # is for the number of the strain, 1-5 for C to NT. The second # is for another suit when needed, such as for Exclusion Blackwood. NEVER actually use "#" in the bid. Instead, it would be something like 4N@30 where 3 is hearts and 0 is ignored.  
    Blackwood, enter 4N@##-P to ask for Aces, 5N@##-P for Kings. If you play that 5N asks for the lowest King, activate that entry and deactivate the entry where 5N asks for total number of kings -- and vice-versa. 
    Gerber, enter 4C@##-P. 
    KickBack and Redwood, enter the level and the suit just below the trump suit, such as 4D@-P (for Hearts), 4H-P (for Spades) etc. ("-P" is the next opponent's bid.) 
    Exclusion, enter something like 5D#32 where Diamonds is a void and Hearts are trumps. 
    Minorwood, enter 4t@ where "t" is the trump suit. 

As always, the ace-asking conventions which are used must be activated and those not used must be deactivated.
The initial Blackwood bids for ace asking are the same for variations such as Roman Key Card Blackwood 1430 as for standard Blackwood. It's only the different response conventions which must be de-/activated.

Show Convention Docs

Seeing the documentation file for a convention can be handy when practicing a convention or entering the auction(s) for it.

Clicking on this menu option will run BidBase File Viewer to display a directory of available convention documentation files arranged in convention card order. At the end of the file the convention files are also shown in alphabetical order, or you can press Ctrl-F to search the document for a convention.

If you do not all the dozens of documentation files for BidBase's programs and conventions, you can view them at www.aeyec.com/BidBase or download them to your computer by clicking the donwload link there.

If you download them, start in the directory where you have the BidBase programs. There should already be a Notes subdirectory there. If there isn't create on, change into it, and un-zip the Notes.


The Bidding Box

The yellow Bidding Box is for you to use to select a player's bid.

If BB bids first, such as when Auto-Bid is turned on, and you do not agree with it, you can click on Edit Bid which lets you import the hand and bidding into the BidBase Editor where you can elect to modify the existing bid or create a new one. Alternatively, after BB bids, you can click a different bid in the Bid Box to just add a new bid as explained next.

When you select a bid in the Bid Box before BB, if BB then makes a different bid, BB's bid will be displayed in the bidding grid to the right of the Bid Box and you will be asked if you would like to add a new bid to supersede BB's. If you do, it will be added and your bid will appear in the bidding grid and you can continue from there.

If you add a bid, it does not replace the entry for the bid BB made. Instead, it will put your new entry before BB's in the datbase. Since BB always uses the bid in the first entry whose specifications match the current hand's, your bid should be used

This feature will not work if the bid you are trying to supersede is part of a convention because conventions, whose Bid Order Numbers are below 900000, always come before non-convention bids which start with BONs of 900000+.

Your new bid will be given a BON starting with 8U0000, so it should come after all convention bid entries and before all the non-convention bid entries. (On computers, "8U0000" comes after "899999".) After "8U", the next digits will be 1-7 for C, D, H, S, N, D, R and 1-7 for the level. So a user bid of 3N would be "8U5300".

The BONs are not unique. Every with the same opening bids and a new bid of 3N will have the same BON of "8U5300".

The following hand data will be saved in your new entry:

  • HCP 
  • Total points including distribution 
  • Number of winners and losers in the hand. 
  • Length and HCP for each suit. 
  • The cards in the hand in the Test Hand field. 
  • Vulnerability. 
  • Bidder's table position (1st-4th) as determined by opening passes.
    (If opening passes were irrelevant to the bidding, change Dealer
    to the first bidder and click Repeat.)

If the above technical info seems confusing, there's nothing to worry about because BB handles making the new entry. All you have to do is click a button.

The reason for adding the new entry is so that the next time the same auction comes up and a hand has the same specifications you just entered, BB will make the bid.

However, the odds of another hand coming up with all of these exact specifications are pretty low, which is why entries in BB are normally made using ranges of numbers rather than specific numbers. For example, the entry for a strong 1N shows HCP of 15-17, not one entry for 15, another for 16, and a third for 17.

Another example: after bids of 1-P, if opener's partner has 6 HCP, 8 total points, and exactly 3=4=5=1 distribution with HCP of 3=3=0=0 and unfavorable vulnerability, he is going to respond with 2 assuming no convention says otherwise.

But the specifications in BidBase for a 2 response are simply total points of 6-10 and 3+ spades. This one entry would cover a great many hands while a bid saved from the practice bidding would only match a very few hands.

But as more emtries with exact specifications are saved, it becomes easy for software to combine those different entries' specs which have the same bid into just one entry. Example:

    Bid#: 
    HCP 
    Pts 
    S-## 
    S-pts 
    H-## 
    H-pts 
    D-## 
    D-pts 
    C-## 
    C-pts
    1 
    6 
    8 
    3 
    3 
    4 
    3 
    5 
    0 
    1 
    0
    2 
    9 
    9 
    3 
    0 
    3 
    2 
    4 
    0 
    3 
    3
    Specs: 
    6-9 
    8-9  
    3 
    <4 
    3-4 
    2-3 
    4-5 
    0 
    1-3 
    <4
    Here we see two entries of hand specs.
    Both had a bid of 2S after 1S-P was
    bid. If BB saw these, it would delete
    the second entry and change the specs
    first entry to what is shown in the Specs
    column. BB would continue to adjust the
    specs in entry 1 whenever more entries
    were made with the same bid for the same
    prior bids.

If the entry you are making is part of a convention or if there are any parts of the entry you wish to modify, after BB has saved your entry, you can click on Edit Entry to import it into BB Editor where the entry will be displayed in the edit boxes.


Bid Display

Each bid is displayed as it is made in standard bridge publication format with these possible exceptions:

    N = Notrump
    P = Pass
    D = Double
    R = Redouble


Disclosure Window

Many bid entries in the database have disclosures which are displayed in the white box in the middle of the screen when the program bids.

There may be multiple entries which make the same bid, but with different types of hand specs. Disclosing only the specs for the matching entry would provide more information than a player is entitled to, so disclosures include the specs for every entry which matches the same bid.

An exception is that if the selected bid is from an entry which is part of a convention, only its specs are shown because normally such bids have special meanings which means that their specs are not comparable to other entries./bids which are not part of the same convention.

Scanning the disclosures for every entry matching the bid made lets you see the exact, various specifications for making the bid, but scanning this list is not the most efficient way to get a general overview of what it takes to make the bid.

To get more information about a bid or convention, click the Edit button and view the hand and the bids for it in the BB Editor. The Editor has links to files which provides detailed explanations of conventions.

A BidBase Convention Card has links to documentation files for all the conventions available with BidBase.


Buttons:

Vulner (Alt-V)

The Vulner. button lets you change the vulnerability for the deal. Vulnerability isn't a factor for most of the bids in bidding conventions, and since BidBase is all about conventions, you won't see a lot of entries specifying vulnerability.

Normally, you should keep vulnerability on none since that is the default for the database, and the purpose of the practice hands is to build up the database with new entries.

Changing the vulnerability does not start the bidding over, but you can do so with the next button.

Dealer Button (Alt-L)

The Dealer button lets you change the dealer for the same deal. For example, if South is the dealer, but you would rather see how South would overcall with the same cards, you can make East (or North or West) the dealer instead. Or you may want to change the dealer to see how a hand is opened in third or fourth chair. This option also starts the bidding over, of course.

A checkbox with the work "Keep" to the right of it is for keeping the same dealer until you change it. For example, if you want to practice responding to opener, you will probably want to keep N as the dealer.

Deal Button (Alt-D)

The Deal button starts a new deal. It displays the upcoming deal number so that you can change it to a specific deal number if you wish.

When bidding, after 3 consecutive passes (or 4 when nobody opens) and you have clicked BB Bid for the 3rd Pass, the BB Bid button caption changes to Deal. This is for convenience and has the same effect as clicking the actual Deal button.

Repeat (Alt-R), Back, Forward

Repeat starts the deal over with the same dealer and vulnerability.

If you edit a bid, the program will erase the bid your are editing to allow your new or changed entry to take effect, but Repeat begins the bidding over completely.

Alongside the Repeat button are buttons to let you scroll back and forth through the deals.

Having deal numbers does not mean that there are a limited number of specific deals. Instead, the number is what is used to "seed" the Random Number Generator which determines how cards a mixed up before dealing. The deal number also lets you replay any deal since it will seed the RNG the same way every time.

Battery Left

If you are not using a notebook, you won't see this, but notebookers will see Battery Left displayed to the right of the deal buttons.

BB Bid (Alt-B)

When the program bids, the bid is displayed and the program waits for you to click BB Bid before continuing with the next hand. This gives you the opportunity to edit the bid's entry or to have the program rebid the hand and show you the analysis.

The BB Bid button's caption changes for different situations, but its purpose is always the same -- to cause the program to stop waiting and continue on.

Editing/Adding Entries

The Edit button sends the current hand and prior bids to the BidBase Editor, just like clicking on a bid in the Bid Box except that the Bid Box also sends the bid you click on.


Enter Hands

Image Click the Enter Hands button to manually enter 1 or more hands for a deal. Cards can be selected by clicking on the cards individually or by entering cards into the yellow input box for each hand. 
Before clicking on a card, click on the button by the input box or click on the input box itself to indicate to which hand the selected card should be assigned.. 
Click a card in a hand to return it to the deck. 
An alternative to clicking on cards is to use the yellow hand input boxes. The advantages are that you can paste all or part of a hand into the box instead of having to click on individual cards and likewise, you can delete all or part of a hand at one time. 
If you enter just 1 or 2 hands, you can have the program randomly assign cards to the other hand(s) by clicking on the Deal the rest button. If you enter 3 hands, the computer will give the remaining cards to the 4th hand, so you never have to enter more than 3 hands. 
Having entered hands, you can then have the program bid each hand while you watch, or you can bid the south hand while the program bids the others.


Rebid With Analysis

The Rebid With Analysis button lets you specify one or more bids to have analyzed when the program is searching for the best bid. This allows you to see why the computer is rejecting a bid which you think should be made.

After you click the button, you will be asked to enter a bid. Say it is the opening bid and you want to see why the computer is not bidding 1H. As the computer tests each of the 1H entries in the database, it will show you where/why the current hand failed to meet the specs of each entry.

If a bid of "1x" is shown for an entry, it is because the same entry's specs apply to more than one suit, including the suit you entered.

When a rejected entry is displayed, you can click the Continue button to continue searching, or you can click the Cancel button to discontinue the search.

You can enter more than one bid at a time to watch, such as "1S,1N", or enter "all" to watch all bids.

It may seem odd to see the descriptions of entries in the Disclsure window such as "Bid requires 3rd position and you are in first position" but the point is to be able to examine any entries making the bid you specify to see why the program rejected the bid entries.


Show DDA & LTC

DDA is a Double Dummy Analzyer. It calculates the maximum number of tricks which each player can get in each strain (clubs, diamonds, hearts, spades, notrump) when able to see all the cards. Under those conditions, it is extremely accurate. I have entered many deals from newspaper columns, books, and magazines in which players have been said to make extremely brilliant plays and the DDA has never failed to make the same plays.

The only drawback to DDA is it can make plays which are not technically correct, such as not taking a losing finesse when it can see that playing for the drop wins. Most of the time this does not happen. It might be nice if it would always make the technically correct plays, but sometimes human players also have valid reasons for not making such plays because of bidding or other considerations and the DDA has no way of knowing about such things, so it just always makes the winning plays.

At the very least, it can provide a guide as to whether or not a game or slam might be reachable and whether BidBase entries should bid accordingly. Also, it is usually easy to see if DDA's totals are based on peeking instead of technical correctness.

To further aid in analyzing hands, High Card Points are shown as well as the Law of Total Tricks numbers. LoTT is used in competitive auctions to help decide whether to compete at a higher level. Image

It is not considered reliable above the 4 level and various factors can cause unreliability even at lower level competitive auctions. It is just a guideline.

Another useful statistic is Losing Trick Count which is shown at the end of each line. In theory, 24 minus the LTC for both partners equals the number of tricks the partnership can take in their best suit.

The DDA results are shown at the bottom of the screen where the entries for finding deals are shown. Normally, you should not need to see both of these displays at the same time. If the Find Deals specs are being shown, you can click the Show DDA button to change to that display.

After the DDA results are shown, the next column shows each hand's high card points, then the Law of Total Tricks, and then the Losing Trick Count followed by the calculation for the partnership.

This shows that N-S can take 11 tricks per LTC and per LoTT while the DDA shows they can take 12. The difference to the player is that DDA isn't available to you during bidding while LTC and LoTT are. Image

Here is a deal which seems to show a spectacular failure of LTC, which predicts 11.5 tricks for N-S, versus DDA, which shows at most 8 tricks in hearts.

DDA can see the following plays between West and East; 
     7 - A
     5 - K
     3 - 6
     Q     
Then when east gets in with the
A, he gives west a spade ruff.  
That's 5 tricks for E-W


Image Next is a deal where DDA shows 10 tricks in spades and 9 in notrump while Losing Trick Count shows 11 tricks are pssible in the 8-card fit (spades).

However, when E-W cards are left the same and N-S cards are mixed up and randomly assigned to the two hands a total of 10 times, the average DDA shows only 9 tricks in spades and 8 in NT. The non-averaged DDA is what is shown on the club's web site, because that is what can be made on the deal's specific lay of the cards, but the average DDA is more accurate in the long run. As such, anyone who bid 4 on this deal actually made a mistake but will never know it because DDA showed 4S as the Optimum.

Another point not mentioned before is that LTC is only applicable when a pair has shown an 8+ card fit or 1 player has a self-sufficient suit.

LTC is also not used in notrump contracts though the calculations will be shown here even if the bidding ends in notrump.


File Menu

Save Deal (Ctrl-S)

This menu command appends the current deal to the end of the "SavedDeals.Txt" file in the Notes folder. It can be viewed with any text-based editor such as Notepad or BidBase File Viewer

The purpose is to save interesting hands for later review, it is not for saving a deal which can be reloaded into the program again. If you want to replay a past deal, just make a note of the deal number, click the Deal button, and enter that number.

Load User Deal (Ctrl-L)

In the Options menu is Enter Deals which lets you enter deals from external sources for BidBase to bid. After entering a deal, you are given the chance to save it to disk.

The Load User Deal function will load a saved user-entered deal.

Load PBN Files (Ctrl-P)

PBN stands for Portable Bridge Notation. This is a standard format for recording bridge deals and scores. Many sets of PBN files can be found online. Google for "Bridge PBN files".

If you belong to a bridge club which shows tournament results on a web site, the PBN files for each tournament are likely available online. Image

Download the PBN files into a folder named PBNs which is in the folder where you have the BidBase Bidding Practice program.  
Click on File - Load PBN Event and locate the file you want to view. The file will be loaded and the first board/deal displayed 
To the right of the Deal button is the board number being displayed followed by the name of the file. Below that is the double dummy Optimum score on the board.  
You can scroll through the deals using the left and right arrows. It does this by reopening the file you already selected and loading the next or previous board.  
To load a specific deal, click on the File - Load PBN Deal # menu. It will ask which board number you want.

To quit using a PBN file and go back to computer-generated deals, click the Deal button.

To start the bidding over, click the Repeat button.

Expert Player Analysis: Some PBNs contain analysis for each deal. It usually should be viewed at the end of the bidding, but since a user can skip to the next deal at any time, we are using the Bid w/ Analysis button to display the analysis so that users can view it at any time.

PBN Viewing Options:

As with BB-generated deals, you may want to just practice bidding by hiding all the hands but Souths by clicking Options-Hide Hands or pressing Ctrl-H, then you bid the South hand by clicking the Bid Box.

To learn more about the bidding, you can leave the hands unhidden and click BB Bid to get BB to make each bid.

Either way, if you want to see how BB came up with its bid, you can click Edit Bid.

Comparing BidBase Bids and PBN Bids:

PBN files for some important events contain the complete bidding for each deal. With these, when BB makes a bid which disagrees with what the PBN player made, BB tells you and gives the option of showing the PBN bid or staying with BB's.

If you choose the PBN bid, it is not added to the BidBase, but BB uses that bid in Prior Bids when looking up its subsequent bids.

Again, to change the database entry for BidBase's bid or to add the PBN bid, you can always click Edit Bid.

If BB does not have an entry for making a particular bid, it will Pass. Alternatively, you can get BB to compute a bid using the DDA results at the bottom of the screen.  The first DDA results shown are for the specific lay of the cards for the deal shown. This is not a very accurate result because it can see which way to take finesses, etc. A more accurate method is to use DDA averaging. You can turn this on in the Options menu. 
The only drawback to this that it takes anywhere from 2 to 15 seconds to compute the average DDAs. If this is too long for you, turn it off and then turn it back on when the need arises. Ditto for using 101-bid deal averaging. 
If BB is able to compute a bid, it will show you the bid and ask if you want to save it. If you do, it will create a BidBase entry for the bid in the database; otherwise, it will use the PBN bid so that you can continue comparing BB's bids to the PBN players'. 
Generally, if BB doesn't have a bid, accepting the PBN bid is probably as good as anything, and it is easy to change if you ever need to.

Another thing that may make the bidding not comparable is if a PBN player is not playing the same system as BB or is playing a convention which is not activated in BB. Short of entering their system into BB, there's nothing you can do about this. 
Lastly, in the comments for deal 21 in the Larry Cohen PBN: "Berkowitz, steaming after the previous deal, raised a 14-16 NT to game." - Not all expert bids are technically perfect. Even when experts go through calm, logical analysis before bidding, experts regularly disagree. See any "It's Your Call" column in ACBL's Bridge Bulletin. 
On the other hand, if you can get PBNs with the bidding of top experts in them, how much fun (and educational) would that be to compare BB's bidding and/or your bidding to theirs?


Quit (Ctrl-Q)

This quits the Practice program, saving the last deal number, dealer, and other program options which will be loaded the next time you start the program so that you can continue where you left off.


Options Menu

Auto-Bid (Ctrl-A)

When checked, the program bids all four hands and you just watch. This is the fastest way to just check out and improve BidBase.

When not checked, you bid the hands first (if all hands are visible) and the program then tells you what it would have bid. If only South's hand is visible, you bid the South hand and the computer bids the other hands. These are the best ways to practice the bids you have selected for use in BidBase.

If you and BidBase disagree on a bid and you keep going with the bidding using your bid, BidBase's subsequent bids may not be correct because BidBase believes your bid shows a hand different from what you actually have.

In this situation, you should either edit BidBase to agree with your bid, or change your bid to agree with BidBase's.

If you choose to change BidBase, you must change not only the current bid, but you must also change any entries for subsequent bids for the reason just given -- that the subsequent bids assume that the hand meets the specs in the original entry. This is obviously no longer true once you change (or replace) the original entry.

Hide Hands (Ctrl-H)

When Auto-Bid is turned off, as noted in the previous section, then if you check Hide Hands, you will be able to see and to bid only the South hand and the program will bid the other 3. With Hide Hands unchecked, you can see and bid all the hands and the computer will tell you what it would have bid.

If Auto-Bid is turned on, then Hide Hands is automatically turned off.

Stay on Top (Ctrl-T)

Causes the practice window to stay on top of other windows, such as when you want to be able to use the BidBase Editor to edit entries while using the Practice program.

Press Ctrl-T again to return to normal.

Enter Hands

See the info about the Enter Hands button, above. The only thing the menu offers is the ability to start the Enter Hands process by pressing Ctrl-E.

Mix Up Cards (Ctrl-M)

Select this option to mix up the cards among 2 to 3 user-specified hands while keeping the same cards in 1 or 2 hands.

Sometimes a bid may appear to be bad (or good) because of the specific lay of the cards. This option lets you see how the bid would fare against a different lay of the cards.

For example, you may choose to keep your cards and have the remaining cards reshuffled and redealt to the other three players. Or both you and your partner can keep your cards and have only the opponents' cards redealt.

Re-Mix Same Cards (Ctrl-R)

Once you have specified the hands to mix using Ctrl-M, you can repeatedly press Ctrl-R to keep re-mixing the cards in the same hands. This lets you quickly see many variations of distributions for the same set of cards in 1 or 2 hands to see how the bidding is affected.

Average DDA

Double Dummy Analyzer shows at the bottom of the screen the number of tricks which can be taken by each player in each suit and notrump. The code for this was written by Bo Haglund and is the same code used on many bridge club web sites.

Image

DDA gets perfect results for a given deal by looking at all four hands. For example, it will never take a losing finesse if playing A-K will drop the Q. This can make good bidding look bad and vice versa.

To offset this, BidBase offers the option of seeing the average DDA results. So while DDA may show that a pair can make 7 given the cards dealt, bidding should reflect what can be made on average.

Averaging: First the N-S cards are kept the same while the E-W cards are mixed up and the DDA calculations are made by Bo's module. The number of tricks taken when each suit is trumps for each player is recorded.

After this is done 11 times, the median for the player and suit for the 11 redeals is 6+. If 101 redeals are done, the median is 51+. The median is the Optimum for that suit.

Once the DDA calculation is done for N-S, the same things are done with E-W cards staying the same while N-S cards are mixed to get a better DDA for E-W.

While 11 iterations is not a very large sample size, it only takes less than 15 seconds (and as few as 1 second) to calculate and for many deals, the accuracy is not critical, such as whether one can make 3N, 4N, or 5N. If there is a deal where you want even more accuracy, you can select 101-Deal Average in the Options menu.

Originally either 10 or 100 iterations were done. This was changed to 11 and 101 for which the median is 6 and 51, respectively. This change was made to avoid tied medians of 5-5 and 50-50. So any mentions of 10 or 100 iterations, such as this in the above screenshot, are outdated.

What is called 11-iteration averaging actually requires 22 iterations - 11 for N-S and 11 for E-W. Likewise, 101-iteration averaging requires 202 iterations in total.

The DDA for the deal shown here shows that E-W should make 7S or 7N because the diamond finesse works and the Q drops. But the 11-iteration average shows that on average E-W can only make a small slam and that is in Spades, while the 101-iteration average says that on average no slam makes.

Once you turn on 11-iteration averaging, it stays on until you turn it off, meaning it will automatically calculate the DDA average for each deal displayed, no matter the source of the deal.

The 101-deal averaging only works on the current deal. That is because while using 101 deals instead of 11 yields better accuracy, it takes 30-60 seconds or more, depending on the complexity of the deal and/or what else your computer is doing at the time. On slower computers, it takes even longer.

DDA Averaging - Not Perfect:

Say that west opens the bidding 1N (15-17 HCP) and N-S end up in 4 with 25 HCP between N-S. Declarer knows that west has all the HCP and a balanced hand, so it doesn't make a lot of sense to mix E-W cards up so that east has HCP on some iterations or that west has singletons or voids on some iterations.

Or say that west opens with a 3 preempt. Any mixing of the cards should still allow for west's having 7+ hearts and usually any heart honors which N-S are missing, so again, it doesn't make a lot of sense to use DDA averaging.

However, performing DDA calculations when the opponents have bid requries an understanding of those bids so that when the cards are mixed between hands, the same bids are made. This is very complicated to do and still doesn't go far enough.

Look at these E-W hands from a BB deal:


    KQ6-A976-4-QT983
    JT543-5-Q632-AK7

    DDA: C=11 D=6 H=7 S=11 N=8

According to DDA, E-W can make 11 tricks in spades. This holds true even when N-S cards are mixed.

If East has shown 10-11 HCP, should West bid 4 with his 13 HCP? According to DDA, definitely. This is because of the fit between the E-W hands whereas the bidding could have easily been the same without having the perfect fit. For example what if East had JT543-J5-KQ62-K2? Now in addition to the spade and diamond loser, there's a heart loser and at least one club loser.

The most accurate way to mix the hands of the other players is to also mix partner's and, again, only give each player the cards which result in the bidding remaining the same which, again, is very complicated to do.

It gets worse:

It's already been mentioned that DDA is not realistic when the computer sees that making the "wrong" bridge play, such as playing for the drop of a Queen instead of finessing when 5 cards are out in the suit.

That is a simple example. It is also "wrong" to lead an unsupported Ace against a slam in a suit which partner has not indicated, but I've seen deals where such a lead was the only way to set the contract.

The same applies to other truisms, such as "second hand low" when playing high is the only way to set them yet there is no logical reason to do so other than peeking.

Can't get there from here:

In trying to make DDA bidding more realistic, I came across situations where it simply isn't possible for some optimum contracts. Say that you are playing Stayman, partner opens 1N, and the optimum is 2C.

Now say that responder has 4 hearts and bids 2C and opener bids 2S. Obviously, you can't get to the optimum.


DDA Complications

Complications can arise from the fact that while south, say, may be able to take 11 tricks in diamonds and 9 in spades if he is declarer, north may be able to take 10 tricks in spades and 10 tricks in diamonds and 9 tricks in notrump.

The optimum contract for the pair would be 4S by north.

But if south bids spades first, then he will be declarer in spades and can only make 3S. Now the alternatives are that if north bids NT first, he will be ahead of the pairs who declared spades in the south and tied with those who bid 5D in the south.

If north bids spades first, then he will beat those pairs playing either 3N or 5D.

This isn't a huge conundrum for live play since you will almost never know which of these situations exist, but BidBase knows and must try to adjust for all the possibilities.