Rules on Splinter Bids
The most common splinters are: 1H - 3S/4C/4D. and 1S-4H/4D/4C. These are adequately described as 7-11 hcp, short in the bid suit (never singleton ACE) and in the neighboorhood of 26 to 29 Zar points.
But splinters crop up on other auctions as well. After, for instance, 1C-1M-3D and 1C-1M-4D. Not to mention, 1C-2C-3H, 1D-2D-3S. 1S-2H-4C, and the like. We have hard and fast rules about use of splinters in these situations.
Here are the rules for splinters in GAME forcing situations (before the splinter, or if game force and fit can be easily established without the splinter), or a splinter where the bid is the second one being made by the person making the splinter.
- Splinter never will be a singleton ACE
- After 2/1 GF splinter never with VOID or singleton ACE.
- In support of a major with two suits bid before the splinter, a splinter in support of a major denies DENIES first or second round control of the fourth suit
- In support of a minor in GF situation, a splinter at the three level denies stopper in fourth suit (if one exist), and at the four level promises a stopper in the fourth suit (if one exist).
- The splinters 1m-1M-4om, and 1m-1M-3OM (OM and 0m = other minor), use same rule, no control in off suit, but 1m-1S-4H shows void. With control in off suit, go via 2NT (jacoby by responder).
This type of splinters after a 2/1 GF also allows for picture jumps... let's imagine an auction where you open 1S and partner bids 2H (GF). And give you a couple of hands.
Not 4♣ because you have a diamond control. Bid 3♥ and take your time. Note, 3H promises control outside of majors (not picture jump to 4H)
Bid 4♥ (picture bid), values and controls in the two majors only.
♠ AKxxx ♥ KJxx ♦ Qxx ♣ x, or ♠KQJxx ♥KJxx ♦Qxx ♣x
Bid 4♣, splinter in clubs, fit for hearts, no first or second round control in diamonds. ((NOTE: After 1♠-2♥, an immediate 4NT is 18-19 hcp balanced, not blackwood, although if responder bids again, he replies to blackwood. See rules for 4NT bids.))