Splinter Bids: Showing Support and Shortness in Bridge

A splinter bid is an unusual double jump in a new suit that shows four-card or longer support for partner's suit, game-forcing values and a singleton or void in the suit you bid. Over a 1♠ opening, for example, 4♣, 4♦ and 4♥ are all splinters.

Splinters let partner judge slam in one look: if his cards in your short suit are small, the hands fit well; if he has honors there, they are wasted. They are a standard part of most 2/1 Game Force and Standard American cards, and many Acol partnerships play them too.

A splinter is one level higher than a jump shift. After partner opens one of a major:

Responder promises:

• Four or more trumps.
• Game values: usually about 10-15 HCP (some pairs ask for 12-15), enough for game but not so much that responder wants to drive to slam himself. With a stronger hand, many players start with Jacoby 2NT and show the shortness later.
• A singleton or void in the bid suit.

The bid is forcing to game. You can see what 3♠ over 1♥ means in every system. Opener either signs off in four of the major or moves toward slam.

The splinter changes the value of opener's hand. He looks first at his holding in the short suit:

• Three or four small cards: excellent. None of his points are wasted, and his losers in that suit will be ruffed in dummy.
• The ace and small cards: fine. The ace still wins the first round.
• King, queen or jack: bad. Those honors face a singleton or void and will seldom take a trick. Opener should mentally subtract them.

Then he adds up what is left. A useful rule: if opener's working values (points outside the short suit plus any ace in it) are about 13 or more (a sound opening with nothing wasted), slam is worth investigating. With fewer, he signs off in game, even with a good-looking hand.

Opener's actions after a splinter:

1. Four of the major: sign-off. Responder passes unless he has extra values.
2. A control cue bid in a side suit: slam interest, asking responder to cooperate.
3. 4NT: Roman Key Card Blackwood, when opener knows every suit is covered.
4. The next step above the splinter, in some partnerships, asks whether the shortness is a singleton or a void.

You are South with ♠KJ73, ♥A962, ♦5, ♣KQ84: four spades, 13 HCP and a singleton diamond. Partner opens 1♠ and you splinter with 4♦. The two deals below have the same South hand and two different openers.

Opener with small diamonds. North holds ♠AQ985, ♥K53, ♦743, ♣A2: 13 HCP, all of them working. He has two key cards, South has two, so only the ♦A is missing. He bids 4NT and then 6♠.

Only 26 HCP, but declarer loses just one diamond. South ruffs two diamonds, and North's third heart goes away on South's ♣Q.

Opener with diamond honors. Now North holds ♠AQ985, ♥K53, ♦KQ4, ♣72: 14 HCP, one more than before. But the ♦K and ♦Q face a singleton, so his working values are only 9. He signs off in 4♠, and that is right: on this layout even game is the limit.

More high card points, fewer tricks. That is the whole lesson of splinters: points in the short suit do not count.

Splinter when:

• You have four or more trumps and game values.
• Your shortness is the most important feature of your hand.
• Your hand is not so strong that you want to control the auction yourself.

Think twice when:

• Your singleton is the ace or the king. Partner will downgrade his honors in that suit, but your singleton honor itself is a working card. Many players avoid splintering with a singleton ace or king.
• You have only three trumps. Partner will count on four.
• You are very strong. With 16+ HCP and shortness, start with a forcing raise such as Jacoby 2NT, then show the shortness.
• You are a passed hand. By agreement, a passed hand's splinter shows a fit and shortness with fewer values (a "fit and shortness" invitation). Agree it with partner.

Splinters are not only for responder. Opener can double jump in a new suit to show four-card support for responder's suit, a singleton or void, and a strong hand (about 17-19 points with shape):

• 1♦ - 1♠ - 4♣: four spades, a club singleton or void, a strong hand.
• 1♣ - 1♥ - 3♠: four hearts, a spade singleton or void, strong.

Responder evaluates the same way: small cards in the short suit are good, honors there are wasted. Because opener's splinter shows extra values, responder needs much less for slam.

• Mini-splinters: some pairs use a single jump (for example 1♠ - 3♥ in some structures) as a splinter with invitational values.
• Splinters over minor openings: 1♦ - 3♥ or 1♦ - 3♠ as a splinter raise of diamonds, usually in inverted minors style.
• Singleton or void ask: the next step after the splinter asks which one responder has.
• Splinter by the defending side: after an overcall, a double jump in a new suit by the overcaller's partner can be a splinter raise.
• Self-splinter: a jump showing a self-sufficient trump suit and shortness, asking partner to judge.

The core version is the double jump by responder. Agree that first, then add the others one at a time.

Splinter judgment improves fastest when you see the full deal after every auction. The BridgeDummy Bidding Room gives you random hands bid with EPBot robots, then shows all four hands so you can check whether your slam had wasted values. When a decision is close, our free double dummy analyzer shows how many tricks game and slam really take on the deal.

• Jacoby 2NT: the forcing raise for hands without shortness.
• Slam bidding: cue bids, key cards and the slam odds.
• Exclusion Blackwood: when your shortness is a void.
• Bergen raises: four-card raises below game.