Bidding and conventions
Splinter bids
A splinter bid is an unusual jump in a new suit that agrees partner's suit and shows a singleton or void in the suit you bid. It lets opener judge whether their honours are working, and so whether to bid slam or stop in game.
Why showing shortage helps
Opener holds a normal 14-count with five spades. Responder splinters 4♣, showing spade support and a club singleton. Here is how that affects two similar opening hands.
14 points, none of them in clubs, so every honour is working.
The same 14 points, but the club king and queen are wasted opposite a singleton.
Both hands have the same trump suit and the same point count, yet slam is good with the first and game is the limit with the second. Counting points can't tell them apart. Knowing where partner is short can.
What you need to splinter
- Four or more cards in partner's suit; three isn't enough.
- Game-forcing strength, roughly 13 to 16 support points. Enough to insist on game, but not so much that you have a stronger route available.
- A singleton or a void in the suit you bid, and nowhere else.
13 points, four-card support, a club singleton, and nothing else unusual to say.
How opener answers
Opener now re-values the hand, looking mainly at the splinter suit:
- Wasted values there (♣ K Q x opposite a singleton, ♦ Q J tight opposite a void): sign off in four of the major. Those honours are worth nothing, and the hand is worse than its point count.
- Nothing wasted (small cards opposite the shortage, and the rest of your strength in the other suits): cue-bid an ace and get the slam auction going.
- An ace opposite the shortage sits in between. It still takes a trick, so it isn't wasted, but it gains nothing from the shortage. Count it as a normal card and judge on the rest of the hand.
| West | North | East | South |
|---|---|---|---|
| 1♠ | |||
| Pass | 4♣ | Pass | 4♥ |
| Pass | 4NT | Pass | 5♠ |
| Pass | 6♠ | Pass | Pass |
| Pass |
Voids, and why they are awkward
A splinter shows a singleton or a void, and partner can't tell which. Usually that's fine: both make partner's honours in that suit suspect, though a void is worth a good deal more.
One refinement: a jump to the five level shows a void, leaving the four-level jump as a singleton. It's one more agreement to remember, and many pairs do without it.
Opener can splinter too
After 1♦ — 1♠, a jump to 4♣ or 4♥ by opener is a splinter agreeing spades: four-card support, shortage in the suit bid, and a hand too good for a simple game raise.
It's rarer, because opener more often has a second suit worth bidding naturally, but the logic is the same.
What it costs
You give up the natural meaning of a double jump in a new suit, which is rarely needed. Hands that want to play in 4♣ opposite a 1♠ opening are rare, and any hand with real clubs and real values has a slower route available.
The other cost is that a splinter tells the opponents where your shortage is. The defender on lead now knows what not to lead, and often what to lead instead. That helps them on hands where you stop in game. The slams a splinter helps you bid usually outweigh that cost.