[gwnn]

1♦-1♠-X-3♠
p-p-X-p
4♥-4♠

3♠ is just a weak raise.

[awm]

Of course it exists!

I suppose one has to ask the question of why the delayed 4♠ bid, but I think there are several possible answers that make sense:

(1) 1♠ bidder has a weak four-card heart holding and the subsequent auction indicated that partner probably has singleton there, greatly improving the chance that 4♠ makes.

(2) 1♠ bidder has enough values to be unsure of whether opponents can balance, or enough hearts to be unsure they have a real fit there. Suppose 1♠ bidder thinks that most of the time 3♠ is the limit, but 4♠ will occasionally make (say 20% of the time). It makes perfect sense to want to play in 3♠ rather than 4♠, but to prefer playing 4♠ to defending 4♥.

(3) 1♠ bidder is walking the dog, and thinks this sequence makes him more likely to get doubled in 4♠ which he expects to make. Note that passing 3♠ is not that dangerous if overcaller has a freak with lots of extra spades and not too many points -- usually opponents won't sell to 3♠ and he's much more likely to get doubled in 4♠ this way than by just bidding it.

[andy_h]

yeh it exists. 1S bidder has gathered more information and has re-evaluated. And all the other info awn suggests.

[655321]

Basically no.

Sure, on any one hand you may decide to do something a bit offbeat, but as a general rule any hand that bids 4♠ now would be better off having bid it on the previous round. Once partner has made a preemptive raise, you usually have a fair idea whether 4♠ will have play, or if they are likely to have a game.

For example, if you are saving against 4♥, the auction
1♦-1♠-X-3♠
P-4♠-X-P

forces opener to choose between showing hearts at the 5 level, or never showing heart support. That is usually preferable to

1♦-1♠-X-3♠
P-P-X-P
4♥-4♠

giving the opponents fielder's choice.

[han]

I can imagine that there are hands where you think that they will let you play in 3S but when it turns out that they don't you decide to sacrifice in 4S.

[Echognome]

I'd only like to mention that there are some hands as well where you are always going to 4♠ and want to learn more about the auction. Yes, allowing them room to describe their hands may make it easier for them to sacrifice, but it also allows you find out more information in how you are going to play the hand. Maybe you are already prepared with what you are going to do if they bid over 4♠. I've at least seen this strategy discussed in books.

[Echognome]

It helps sometimes if I read the auction correctly.

[benlessard]

Sometimes they dont have a H fit. Why would i bid 4S if they reach a risky 3Nt or play 4m ?

Once they reach 4H its still possible they are in a 7 card fit but its likely they have a fit so at this point bidding 4S make a lot more sense.

[gnasher]

The decision to bid 4♠ doesn't have to result from a revised evaluation - it can just be insurance.

Suppose that you think that each game has a 30% chance of making, and a 70% chance of going one down. I'm also going to assume that:
- These probabilities are independent.
- The opponents are always going to do the right thing, by doubling when they should and saving when they should.
- We will double 5♥ if they bid it.
- At the other table, teammates will play 4♥ undoubled.
- It's game all.

If permitted, you'd prefer to play 3♠ than 4♠. However, once they bid 4♥, bidding 4♠ gives an expectation of:

Both games make, so they save for 200:       0.3 x 0.3 x 13 = +1.2
We make, they don't, so they save for 500:   0.3 x 0.7 x 15 = +3.2
They make, we don't:                                      0.7 x 0.3 x 9 = +1.9
Both games fail:                                              0.7 x 0.7 x -7 = -3.4

So our expectation from bidding 4♠ over 4♥ is positive, even though we think that both games are likely to go down.

With the above assumptions, the break-even point is when each game has just over a 20% chance of making.

[hotShot]

If 3♠= is a good result for our side or 3♠-1 is a good save against opps partscore, than 4♠-1 or 4♠-2 should be a good sacrifice against opps gamescore.

At this board the bidding suggests that the player in 3rd hand has ♠ single or void, so that the defensive value of the ♠ drops. It also suggests that opps remaining values will fit well, so they are probably making 4♥.

[neilkaz]

han, on May 22 2008, 09:17 PM, said:

I can imagine that there are hands where you think that they will let you play in 3S but when it turns out that they don't you decide to sacrifice in 4S.

Me too. It's generally good when there's any doubt, to bid 4♠ over 4♥ although cautiously at unfavorable colors.