How could I know to go for 3NT over 4S

[Antraxxx]

North deals and opens 2NT (20-21, favorable vulnerability if it matters). I'm holding [hv=pc=n&s=sq743h743dk4c9872]133|100[/hv]

So with 5 HCP we probably want to be in game. I 3♣, he 3♠ and I raise to game in spades. His hand was this:

[hv=pc=n&n=sakj5hk95daj5ca53]133|100[/hv]

Despite the Ah and Qd being onside, after a Qc lead partner gave two hearts and two clubs for one down. So in hindsight we belonged in 3NT. I remember a post in this forum that gave some guidelines on when to prefer a NT game to a major suit game, but it was geared more towards the 1NT opener - as a responder to 2NT it's difficult to know if the honors are in the short suits or not, for instance. So, how could this have been avoided? Should north have downgraded his hand for being 4-3-3-3 and opened something else? Or maybe declined stayman because of his shape? Or should south have recognized some feature of his hand and avoided stayman?

 

Thanks.

[wank]

on your hand 4♠ was clearly right. that it went off and 3nt makes is just bad luck. i suspect it also involved some dodgy declarer play from your partner too as he should only lose 1 heart trick if the finesses are right - he can finesse a diamond and discard one of dummy's hearts then ruff a heart later. trumps probably need to break well admittedly.

 

in general don't worry about this stuff - it's quite advanced.

 

but just for your info, when responder knows to 28+ points and isn't interested in slam is the classic time to avoid stayman and play 3NT.

 

To a lesser degree 4333 shapes are less suited to stayman - the problem here though is that even if you're balanced, partner might have a weak doubleton for his 1NT opener, so will take ruffs in his own hand even when you're flat. opener with 4333 should not mastermind.

[cherdano]

You can get this decision right on some auctions, but not on others. Over a 2NT opener, you don't have the space (unless responder decides to skip Stayman with a 4333 hand, which is probably right more often than not but still a guess).

[Siegmund]

If you somehow magically knew that partner was 4333, you'd prefer 3NT unless you had some significant shape in your own hand (any singleton, and perhaps a small doubleton - here you had Kx.) In a real-life non-relay system you'll never know that, and responder's choice of the major with 4432 and no extra values is completely normal.

[Wackojack]

Yes this looks like a "dont worry" hand if you get to game and it fails. South has a poor 5 count, so you already know that opposite a 20 count, a game contract might be pushy. It looks like 3NT has marginally the greater chance since the defence is more likely to lead a low heart holding the ace giving declarer an extra trick. With A♥ and Q♦ onside you make a lucky 3NT or 4♠ unless there is a freak break.