[Knurdler]

When I open and my partner replies with a 6-9 point range limit bid, I think it might be useful to know what the probabilities of his hand being minimum (6/7) or maximum ( 8/9).
To simplify, let’s assume just 2 cases: opener has 13 and opener has 18 points. Opponents are silent.
I have tried Richard Pavlicek and Durango Bill websites without success. Is there a maths genius who can answer?
To clarify my question, the format of the answer I am looking for is: if opener has 13 points, responder will have 6/7 27% of the time and 8/9 73% of the time.

[smerriman]

https://www.bridgeba...aler/dealer.php

produce 10000
condition hcp(south)==13 and (hcp(north)>=6 and hcp(north)<=9)
action frequency (hcp(north),6,9)

This gives around a 54% chance of 8-9 points, while if you change to an 18 count it's around 48%. I'm unsure what relevance this would have to how you actually continue though.

Obviously highly simplified, not counting shape, what opportunities the opponents had to bid and didn't, etc.

[PrecisionL]

What is a Limit Raise? According to some experts it is 9-11 hcp AND 3 cover cards!

What is a cover card? George Rosenkranz years ago proposed A + A + Q of Trumps = 10 hcp, or A + K + K & 4 trumps = 10 hcp, occasionally 3Ks = 9 hcp (assuming not opposite a void or singleton).

A singleton (in dummy) can count as a trick (cover card).

QJx QJx QJx xxxx us NOT a Limit Raise.

[bluenikki]

PrecisionL, on 2024-September-27, 16:48, said:

What is a Limit Raise? According to some experts it is 9-11 hcp AND 3 cover cards!

What is a cover card? George Rosenkranz years ago proposed A + A + Q of Trumps = 10 hcp, or A + K + K & 4 trumps = 10 hcp, occasionally 3Ks = 9 hcp (assuming not opposite a void or singleton).

A singleton (in dummy) can count as a trick (cover card).

QJx QJx QJx xxxx us NOT a Limit Raise.

A limit raise is 4 potential cover "cards."

[johnu]

PrecisionL, on 2024-September-27, 16:48, said:

What is a Limit Raise? According to some experts it is 9-11 hcp AND 3 cover cards!

A limit bid is not necessarily a limit raise.

---

2NT invitational is a limit bid and has nothing to do with a limit raise as commonly used.

[apollo1201]

In all cases, the answer to the question is not really useful.

With 13, barring extreme shape, there won t be game, whether responder is min or max.

With 18, you bid game (unless it is a downgraded 5332).

The question is more useful with hands in between, should I risk going down in 3M if partner is min in case we can bid game

Some judgment is required and extends well beyond pure HCPs. Quality of honors, shape, secondary suits, hands that fit well or not together, etc.

Game tries and how many covers you need are more useful in this context than pure HCPs. Futthermore, to increase the safety of your tries, you can decide that lousy 6-7 bid 1NT so that the raise is sounder and semi constructive.

[apollo1201]

In all cases, the answer to the question is not really useful.

With 13, barring extreme shape, there won t be game, whether responder is min or max.

With 18, you bid game (unless it is a downgraded 5332).

The question is more useful with hands in between, should I risk going down in 3M if partner is min in case we can bid game

Some judgment is required and extends well beyond pure HCPs. Quality of honors, shape, secondary suits, hands that fit well or not together, etc.

Game tries and how many covers you need are more useful in this context than pure HCPs. Futthermore, to increase the safety of your tries, you can decide that lousy 6-7 bid 1NT so that the raise is sounder and semi constructive.

[PrecisionL]

bluenikki, on 2024-September-27, 17:25, said:

A limit raise is 4 potential cover "cards."

A hand with trump support and 4 cover cards is a Game Forcing raise (Jacoby 2NT or however you play GF raises).

A hand with trump support and 3 - 3 1/2 cover cards is a Game Invitational Raise (per Rosenkranz in several of his books through 1996).

NOTE: Rosenkranz counts Qxx opposite xxx or better and xx (with 4 trumps) as 1/2 cover card.