[mw64ahw]

nullve, on 2024-February-28, 02:55, said:

JT9
JT9
JT9
JT92

hcp + number of cards (strictly) above 8: 4 + 12 = 16

T98
J98
J98
JT98

hcp + numbers of cards (not necessarily strictly) above 8: 3 + 13 = 16

I guess you don't have many plus scores by bidding after 1NT on these hands and that's before you consider whether to go on to 3NT

[thepossum]

smerriman, on 2024-June-02, 14:47, said:

I'd just bid game. If you're playing IMPs, you only need to make 45% of the time (non-vulnerable) or 38% of the time (vulnerable) to make a profit - i.e. you can still make a profit even when making the contract less than half of the time. If you're playing MPs it's of course 50%; obviously hand evaluation is a complex topic that comes down to significantly more than just HCP, and thus there will be some hands where it's better to pass, but I'd just keep things simple here rather than trying to "guess" and think you've made a mistake when you've "guessed wrong".

A profit on points or IMPs?

[DavidKok]

Those are the traditional IMP odds.

Let's say you are vulnerable, and you are taking either 8 or 9 tricks in NT (but you don't know which). If it's 9 tricks, bidding game wins +450 points (+600 vs +150) or 10 IMPs compared to staying low. If it's 8 tricks, bidding game loses -220 points (-100 versus +120) or -6 IMPs compared to staying low. And 10:6 odds happens to be 62.5%, or ~38% chance to make being break even. Similar calculations when not vulnerable produce 45%. Generally this is teams logic, though the same argument is also a solid guideline at crossIMPs, butler, or some other form of IMP-based scoring.

[mikeh]

One of the issues raised by the OP, in later posts, is how to make a decision after a bidding sequence in which opener showed a balanced 11-14…1m 1M 1N.

As I understand it, historically a 1N opener was 16-18, and people passed most flat 12 counts in 1st and 2nd seat.

Experts recognized (eventually) that it was far better to open most 12 counts, but doing so meant that the notrump rebid went from 13-15 to 12-15. A 4 point range is problematic. Responder has to invite with hands where game has decent chances opposite 14-15 but those hands will generate minus scores fairly often when opener has 12-13…not ‘most of the time’ but enough to be a concern.

In addition, back then, bidding methods were getting more sophisticated, and responding structures over a strong 1N were some of the earlier ‘good ideas’ discovered or invented. Accordingly it became popular to use 15-17 1N, which remains the default (in the strong 1N community) to this day.

However, just as in the 1970’s players began seeing a 12 count opener as normal, on flat hands, nowadays most players, at all levels beyond beginner, open a lot of 11 counts. When one does so and still uses 15-17 1N openings, one has reinvented the problem that the old 16-18 range created once 12 count openings became normal…the 1N rebid is too wide a range.

This is, imo, part of the rationale behind an increasing move, especially amongst advanced and expert pairs, to use a 14-16 1N opening range. That allows the 1N rebid to be 11-13, which is a much easier range for responder to cater to in his invite or pass decision.

A difference of 1 hcp may not seem like much but my experience suggests it’s an important factor. One of my former partners liked a 11-14 1€N opening. I played it because I generally play what my partner prefers, but I hated it. We had too many 2N down 1. You hold a balanced 11 count and it’s dangerous to pass because, with balanced hand opposite balanced hand, 3N will make around 50% of the time if opener has 13-14, but 2N will fail fairly often when opener has the more likely 11.

So if you’re looking for guidance on how to resolve the invite or pass decision, when opener rebids 1N, you have three choices. One: accept that you’re going to guess wrong (either in deciding whether to invite or whether to accept partner’s invite) more often than you would like….your methods cause the issue…or switch to 14-16 1N, allowing the rebid to be 11-13, or stop opening flat 11 counts.

On that last point: in my current main partnership, we open very aggressively. We basically never pass 11 counts, open a lot of shapely 10 counts, and we play 10-13 1N not vulnerable (14-16 vul). The 10-13 violates my preference for a 3 point range but partner was opening 10 counts when our agreement was 11-13, and it was easier just to make it systemic (and avoiding having to announce ‘11-13 but he does it with 10 as well).

[nullve]

mikeh, on 2024-June-07, 12:38, said:

We basically never pass 11 counts, open a lot of shapely 10 counts

The set of all 11 counts certainly includes hands with less trick-taking potential than the average balanced 10 count. So do you also tend to open average-looking balanced 10 counts? If not (and it seems like you don't unless you can open a 10-13 NT), why not?

[mikeh]

Your reasoning is fallacious. One might equally argue that some 9 counts have more trick taking potential than some 10 counts, so why not open 9 counts?

My take on your attitude towards the game, based on many posts, is that you aren’t much of a believer in the partnership aspect of the game, which goes a long way towards explaining your post.

There are a number of reasons for setting 11 as the baseline for a vul 1x on a balanced hand.

One (which I suspect was apparent to most but missed by you when reading my earlier post) is the use of a notrump ladder…a topic on which DK and I basically agree. Given 14-16 1N red, we want a 3 point range for 1m 1x 1N (in fact, since we transfer over 1C, we will accept a transfer to 1M with a balanced hand and fewer than 4M, but 1C 1D 1H usually shows a balanced 11-13, thus the equivalent to a non T-Walsh 1N rebid)..

Opening 10 counts makes the range of opener’s rebid too wide.

Second: only someone who approaches the game as if it were some form of solitaire or poker thinks that they can unilaterally determine the trick taking potential of a minimum range balanced hand before the auction begins.

Those of us who play a partnership game understand that partner is involved in decision making, whether in competitive auctions or purely constructive ones. We understand that cards that, in our hand considered alone, don’t offer much by way of trick taking potential, may combine with partner’s cards quite nicely.

It helps partner to evaluate accurately when our hand is well defined. Playing 11-13 as our minimum vul 1x range is, on the whole, more useful than would 10-13 be. Obviously, some 10 counts will fit better than some 11 counts but in the long run the 11 counts will usually be more useful to partner than the 10 counts…and his being able to play me for at least 11 can make or break a decision he ends up facing.

Before you jump up, yelling ‘gotcha!’ because this seems inconsistent with playing a 10-13 1N opening bid….

Opening 1N, weak, has a significant preemptive value. However, in auctions that go 1m (P) 1x (P) 1N, we rarely need a preemptive effect…both opps have passed despite being able to act at the 1 level. So while 10-13 is, imo, too wide a range, much of the cost of that is offset by the preemptive value.

In addition, note that we only play 10-13 1N when nv. While 11-13 doesn’t promise absolute safety in 1N reached after 1m 1x 1N, it’s definitely safer than doing it on a 10 count….especially since we respond to 1C (nf, 2+) on most 3 counts. Vulnerable undertricks hurt, lol.

[nullve]

nullve, on 2024-June-07, 13:49, said:

The set of all 11 counts certainly includes hands with less trick-taking potential than the average balanced 10 count. So do you also tend to open average-looking balanced 10 counts? If not (and it seems like you don't unless you can open a 10-13 NT), why not?

mikeh, on 2024-June-07, 14:19, said:

Your reasoning is fallacious. One might equally argue that some 9 counts have more trick taking potential than some 10 counts, so why not open 9 counts?

One could equally argue that if, analogously, you basically never passed 10 counts and opened a lot of shapely 9 counts. But it doesn't seem like you do.

[thepossum]

DavidKok, on 2024-June-07, 03:54, said:

Those are the traditional IMP odds.

Let's say you are vulnerable, and you are taking either 8 or 9 tricks in NT (but you don't know which). If it's 9 tricks, bidding game wins +450 points (+600 vs +150) or 10 IMPs compared to staying low. If it's 8 tricks, bidding game loses -220 points (-100 versus +120) or -6 IMPs compared to staying low. And 10:6 odds happens to be 62.5%, or ~38% chance to make being break even. Similar calculations when not vulnerable produce 45%. Generally this is teams logic, though the same argument is also a solid guideline at crossIMPs, butler, or some other form of IMP-based scoring.

My query simply relates to who you are playing against?
Are they the same odds between a few mates down at the club or Team USA - excuse my ignorance do I mean Poland or Turkey or Netherlands - I am out of touch (EDIT sorry Switzerland and others)
And realising I am in friendly NB territory all theoretical probabilities assume you know how to make your contracts - maybe not the probabilities but the likely scores. Double Dummy is always a problem when you have NB play up against best defence or vice versa - at IMPs is that effect not doubled - lets go for handicap system of scoring
I am always looking for friendly average me-level teams

[nullve]

mikeh, on 2024-June-07, 14:19, said:

There are a number of reasons for setting 11 as the baseline for a vul 1x on a balanced hand.

One (which I suspect was apparent to most but missed by you when reading my earlier post) is the use of a notrump ladder…a topic on which DK and I basically agree. Given 14-16 1N red, we want a 3 point range for 1m 1x 1N (in fact, since we transfer over 1C, we will accept a transfer to 1M with a balanced hand and fewer than 4M, but 1C 1D 1H usually shows a balanced 11-13, thus the equivalent to a non T-Walsh 1N rebid)..

Opening 10 counts makes the range of opener’s rebid too wide.

Second: only someone who approaches the game as if it were some form of solitaire or poker thinks that they can unilaterally determine the trick taking potential of a minimum range balanced hand before the auction begins.

Those of us who play a partnership game understand that partner is involved in decision making, whether in competitive auctions or purely constructive ones. We understand that cards that, in our hand considered alone, don’t offer much by way of trick taking potential, may combine with partner’s cards quite nicely.

It helps partner to evaluate accurately when our hand is well defined. Playing 11-13 as our minimum vul 1x range is, on the whole, more useful than would 10-13 be. Obviously, some 10 counts will fit better than some 11 counts but in the long run the 11 counts will usually be more useful to partner than the 10 counts…and his being able to play me for at least 11 can make or break a decision he ends up facing.

Playing you for at least 11 works better if you don't open 11 counts you believe are no better than some of the 10 counts you'd pass with. Right now your 11-13 range is effectively 10-13 and also overlapping with your 0-10 pass opening range on balanced hands.