Splinter

Double jump = Singleton,
Triple jump = Void

See Splinter for the basic Splinter bid.

In this variation, a double jump shift shows a singleton in the suit bid while a triple jump shift shows a void. Because it forces responder to a higher level, it should show more HCP and/or distribution.

Examples:

1	1 = no jump (4+ Spades) 2 = single jump (6+ Spades, weak or strong as agreed) 3=double jump (singleton Spade) 4=triple jump (void in Spades)
1	2 = no jump (4+ Diamonds) 3 = single jump (6+ Diamonds, weak/strong) 4=double jump (singleton Diamond) 5=triple jump (void in Spades)

Also see Random Splinters, which allow you to show voids below the game level (e.g.: 1-4) in response to 1 of a major without identifying the short suit.

Extra Trump for Minor Suit Jump Raises:

In response to 1 or 1, a splinter (as well as a limit raise) normally shows extra trump support. For example, a single raise just promises 3 of the major, but a limit raise or a splinter shows at least 4.

If this is applied to minors, where a single raise of Diamonds shows 4 (according to SAYC) and a single raise of Clubs shows 5, then limit raises and splinter raises should show at least 5 Diamonds or 6 Clubs.