[jlango]

I've played a lot of rubber and recently started playing at my local club.

I've heard sometimes it is better to bid a contract you can't make than it is to let your opponents have a successful contract. Is this true and can anyone give examples of this? How can you figure out when you want to do this?

How should vulnerability affect bidding strategy?

Is it possible to have > 100% if your opponents make mistakes and you play perfectly?

Any other tips?

[ArtK78]

In life, as in bridge, it is not possible to have more than 100%. That is a tautology.

As for bidding a contract that you can't make being better than letting your opponents make a contract, that is fairly easy to explain. If you can make 10 tricks in hearts and the opponents can make 10 tricks in spades, it is better to be in 5♥ down one (even if doubled) than it is to let your opponents bid and make 4♠. This particular example is valid no matter what the vulnerability. However, suppose you could make only 9 tricks in hearts but your opponents can make 10 tricks in spades. Now it is right to bid 5[he} and be doubled failing by 2 tricks only at equal or favorable vulnerability (both sides vulnerable, both sides nonvulnerable, or your side nonvulnerable when the opponents are vulnerable). In each case, you score better for down 2 doubled than you would for letting your opponents play in 4♠ making. But if you were vulnerable and your opponents were not vulnerable, you would score worse by being down 2 doubled in 5♥ than if your opponents played in 4♠ making.

I did not provide the scores - you should be able to work them out.

When not vulnerable against vulnerable opponents, it pays to be even more agressive. Down 3 doubled nonvulnerable is better than allowing your opponents to make a vulnerable game.

But beware - down 3 doubled nonvulnerable is not much better than allowing your opponents to make a vulnerable game. And if you can beat their game the sacrifice will be very costly.

[Stephen Tu]

You ask for duplicate (IMP) strategy, but I think you are perhaps a bit confused, and want duplicate (MP) strategy. Most duplicate club games, if pairs, are scored as "matchpoints", MP, not "international matchpoints", IMP. Team games (Swiss teams, knockout tourneys) are more often run as IMPs. Although it is possible to have IMP pair games and MP team games (aka board-a-match, BAM), these tend to be run more rarely.

In matchpoints, it only matters *whether* you beat the score at the other table(s), you get 0/1/2 (or equivalently 0/0.5/1) for losing/tying/beating each other table, with your final score usually expressed as a percentage of the max theoretical possible score (50% being average, winners typically in the 60%+ range at a club game). So being -100 in your contract a very large triumph if most other tables are say -110 or -140 in the opponents contract, same for being -500 in say 5c-x rather than -620 at 4sp the other way. At IMPs on the other hand, it is closer to rubber bridge, in that the *amount* you beat the other tables by also matters. At IMPs, small differences are only worth a small # of imps, so sacrificing (deliberately bidding a contract you know you probably won't make) is less frequent.

For the rest of this post I will describe MP strategy.

jlango, on 2013-July-06, 18:37, said:

I've heard sometimes it is better to bid a contract you can't make than it is to let your opponents have a successful contract. Is this true and can anyone give examples of this? How can you figure out when you want to do this?

Generally it's when you have a lot of trumps and a lot of distribution, and favorable (best) or equal vulnerability. You have to be able judge how many defensive tricks your side has (you don't want to sacrifice if they are going down), and how many tricks your side will probably make (you don't want to go down more than the value of their contract, after they double you). This judgment comes from experience.

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How should vulnerability affect bidding strategy?

You can bid more aggressively non-vul, because being doubled down 1 (-100) will usually be quite good, better than the opps making a partial for 110-140 their way. Vulnerable, you have to be more careful against good opponents especially competing to the 3 level, because they will be doubling you aggressively, attempting to achieve +200 for down 1, which will be very bad compared to a partial their way. You also have to be more careful when vul since *not doubled* going down 2 is usually also really bad. Sacrificing, you have to be very careful vulnerable vs. not, because -2 doubled (500) is worse than letting them make a game (400 something). On the flip side nv vs. vul you can be a little crazy if you are reasonably certain they are making, since -3 dbld your way is still an improvement.

That's for competitive bidding. Constructive bidding, at MP the vul doesn't affect your decisions much, since you are shooting for > 50% games, slams. It's only at IMPs that you overbid a bit to reach vulnerable games which have a large IMP bonus compared to the penalty for going down.

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Any other tips?

At matchpoints, if you are what appears to be a normal, common contract, whether declaring or defending, you are generally supposed to target taking the most tricks *probable*. That means usually *not* taking safety plays as declarer, if they give up a trick to the most common breaks. On defense, this often means playing to prevent overtricks, instead of trying all out to defeat the contract as is more commonly right in rubber / IMPs. Don't play for a low percentage holding from partner if doing so will give up a trick more often than setting the contract.

[BillPatch]

It should be noted that the majority of the competition on BBO is scored at IMPs pairs, both in the main playing room, the relaxed lounge, the ACBL and BBO masterpoint awarding tourneys. Novices and beginners who want more info on imp pair strategy who plan to play here on line may search this forum for advice, or ask a new question.

[1eyedjack]

I think that sacrificial bidding has its place in rubber bridge. The immediate benefits are less obvious, perhaps, and it may be less prevalent in consequence. If the opponents are vulnerable and bidding a making game which would also net them a 700 rubber bonus then you might be right to bid to go down on that hand in the hope that the cards fall your way next hand (which they will half the time). When duplicate was invented the penalty and bonus structure was intended to reflect the strategic value of a score in a rubber context as well as immediate score. I don’t think it does a brilliant job at that, but no complaints. A different game perhaps but none the worse for that

[PhilKing]

Where do you play rubber bridge?