Double or Bid Five

[gurgistan]

It is a common enough scenario, we compete in hearts and they compete in spades. We get to 4♥ and they bid...4♠.

 

We have two options: bid on to five or double for penalties.

 

Leaving it undoubled seems clearly wrong.

 

Opponents have to go down 3 tricks doubled for us to earn more points than we would have playing game in hearts (assuming of course, that we make).

 

How do we decide we are going to set by 3 tricks? It helps to have their trump Ace and Aces and Kings in suits other than hearts.

 

If we cannot set by at least 2 tricks then we should bid on. Setting by 2 tricks is not as valuable as making game in hearts but should be better than going 1 down in 5♥.

 

It is possible that 5♥ makes which is better than setting by 2 but not by 3.

 

Am I reasoning this common situation rightly. Is my maths right?

 

If I am misunderstanding something here could someone please point it out.

 

Many thanks.

[hotShot]

There are 4 cases to look at:

 

1) 4♠ and 5♥ are both down

Don't bid 5♥.

 

2) 4♠ makes and 5♥ are down

You should bid, if you being down is cheaper than 4♠ depending on vul.

 

3) 4♠ and 5♥ both make

You need to bid 5♥.

 

4) 4♠ is down and 5♥ makes

You should bid, if 4♠ is less than down (2)3 depending on opps vul.

 

Before you do the math you need to know which of the 4 situations applies.

[karlson]

See if you can get your hands on a book about "the law of total tricks".

 

But briefly, there are a few things you should think about.

 

1. You don't mention the vulnerability. Assuming you think 4s is definitely going down, you only need to beat it 2 for it to be better than your game at white/red (meaning you are not vulnerable but the opponents are), but you need to beat it 4 at red/white (the opposite situation). 3 is right at equal vul.

 

2. The most important things to think when deciding to defend or bid on are

a) the number of trumps (hearts) you and your partner have. With only an 8-card fit, it'll almost never be right to bid 5, with an 11-card fit, it'll often be right.

b) the number of trumps (spades) you think your opponents have

c) the degree of your secondary fit. If partner promised a side 5-card suit and you have a singleton, generally defend. If you have a big double-fit, generally bid.

d) the number of honors in the opponents' suit. You mention the ace of their suit, but that card will actually be ok for bidding also. Kings, and queens however, are a big sign to defend.

 

In general keep in mind that your partner is also thinking about the same things you are and may be better placed to make a decision.

[gwnn]

In Matchpoints it's sometimes very important to bid on.

 

650 is a much much better score than 500, with possibly a bigger edge than -100 vs +500

 

In IMP's it's generally speaking not so important to bid on, except if you think there's a reasonable chance they both make. If you think there's at least a little chance of that (everyone seems to have crazy shapes), you need to bid on in IMP's much more than at MP's. This is because in MP you only get a zero or a bad score (but in practice in these big competitive decisions you usually have at least a little company, no matter how unsuccessfully you decide) while at IMP's these results can be incredibly painful. 650+620=15 IMP's. Much worse than just a zero at MP.