Research
A study of 100,550 deals. Controls and losers find slams a point count never reaches, but one hand cannot decide alone: the pair has to show them to each other below game.
Some slams hold far fewer than the 33 points the point count asks for, because the two hands hold every control and few losers. A hand looking at four of its major has to decide whether to bid game or make one more try below it. This measures which hands should try. “Slam is sound” below is the share of hands where the small slam made on at least three-quarters of the redeals, and “points a deal” is what bidding six gained over bidding four.
Judged on its own hand only, the player who is thinking about a slam is wrong more often than right. These are the hands at the point where four of the major is the alternative:
| The hand at the four-of-the-major decision | Hands | Slam is sound | Points a deal |
|---|---|---|---|
| 5 or more controls (ace 2, king 1) and 6 or fewer losers | 7,816 | 27% | −88 |
| 6 or more controls and 5 or fewer losers | 3,064 | 36% | +7 |
| 7 or more controls and 5 or fewer losers | 1,693 | 41% | +50 |
So a hand with fine controls and few losers should not bid a slam by itself. What it should do is ask: a control bid below game costs nothing, and the answer is what makes the difference.
| The two hands | Sides | Slam is sound | Points a deal |
|---|---|---|---|
| The try (6 or more controls, 6 or fewer losers) opposite 4 or more controls and 7 or fewer losers | 726 | 80% | +444 |
| Both hands 5 or more controls and 6 or fewer losers | 468 | 84% | +490 |
| Both hands 4 or more controls and 6 or fewer losers | 1,546 | 60% | +254 |
| 12 or fewer losers and 10 or more controls between the hands | 2,500 | 79% | +437 |
These are the slams a point count never reaches. The sample held 416 such sides with under 30 high-card points, of which 263 make a slam. The app bid 128 of those, and on 90 of the ones it missed, neither player ever made a slam try.
The rule as measured is not in the app. It was built and tried: with a major agreed and game certain, a hand holding five or more controls and six or fewer losers would show a control below game instead of bidding game. Inside the app’s existing control-bidding sequences those numbers turned sound slams into stops in game, so it was withdrawn.
Most of the ground it covers is now held another way. With Serious 3NT switched off, once a two-over-one has agreed a major, any hand holding a control below game shows it, which is what this study argues for on the hands it measured. With Serious 3NT on, 3NT stays the slam try and a control bid keeps that convention’s meaning.
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