[awm]

This question comes in part from the discussion of the value of system versus card play. I'm wondering where, in team matches, most of the imp swings are generated. My experiences have indicated the following:

Once a fairly high level of play is reached, the vast majority of imps are swung in bidding decisions. What I mean here is, there are relatively few hands where the same contract is played at both tables, making at one and down at the other. Of course there do exist interesting play and defensive problem hands, even for strong players. But my feeling is that the bidding decision hands are much more frequent and frequently expensive.

Now admittedly, I'm not playing a lot of hands against players of Fred and Bob Hamman's caliber. But my observations from kibitzing the top players (and those matches I've played against them) have been much the same. It'd be interesting to see some actual analysis of this -- it would be fairly easy to do (just calculate imps gained/lost when playing the same contract at both tables, versus imps gained/lost when the contract is different).

Of course, none of the above applies at a more intermediate level when easy play problems will be frequently misplayed. Getting past this level depends much more on play/defense and less on bidding.

If we take it as a given that most imps are swung on bidding decisions, it seems straightforward that it will be easier to make the right choice (and thus win imps) if we have as much information as possible with which to make the decision. Since different systems can present different information, it seems pretty clear that system will make a difference...

However, I also suspect that the vast majority of imps swung in the auction, are swung in competitive auctions. This too, we could probably determine via analysis of top flight matches. If it's true, this would suggest that the advantage of playing a relay system for example (which carries great benefits in non-competitive slam bidding) may be more than counterbalanced by the disadvantage of having less informative calls early in an auction when the opponents will intervene.

Another interesting note, I've observed that when the same contract is played at both tables, and makes at one and not another, more often than not the opening lead was the critical decision point.

Anyways, I'd be interested whether other players' experiences match my own, and I'd definitely be interested if someone has a database of hands played by top players and could run some analysis.

[reisig]

so many variables ...impossble anwer ...and question

[hotShot]

Your observation is right, and you should have expected it that way.

1) Players at the top level will usually find a good/working way to get the most tricks possible, without risking too much. So logically the imp swing depends on the contract they bid.

Short: equivalent playing skill makes bidding the deciding factor

2) If a world class player can make 3NT in a hand and you can't, then you should not bid it. You will loose less imp's making 2NT, than loosing in 3 NT.

3) The most difficult things in bridge are:

• the opening lead
  
• competitive auctions

it is logical that most swings are caused by one of the above.
In both cases you have to make decisions without knowing all the facts.
At the opening lead, you haven't seen the dummy yet, in competitive auctions bidding space is lost, that is needed to exchange information. If you have all informations you can decide, if your informations are incompleat you must guess. A guess can be wrong and will therefor create a swing.

[winkle]

Here are some points:

I think defense matters a lot, even at high level competition. I think the biggest difference between the best in the world and the next-tier experts is how well they defend.

I think most people over-value the importance of bidding versus play. The reason they over-value bidding is because when they see a swing board where the final contracts at the two tables are different, they automatically assign the cause of the swing to the bidding. This only makes sense if the fate of the contract is clear cut. Even if the bidding has determined that there *will* be a swing, the play will often determine *which direction* the swing will go -- surely that's at least as important!

Luck plays a bigger role in bidding than in play. Even if we accept as fact that bidding creates more swings than play, the extra swings can be due to luck rather than skill.

[Fluffy]

From my experiencee when all pairs play same base system such as 5 card majors, strong NT, there aren't as much swings from bidding, and play, and specially leads come into the equation.

[pigpenz]

Basically it comes down to judgement and proper technique. Look at the hands palyed on BBO, where you can watch the movie and see what Deep Finesse says are the correct cards to play and not play. More than likely the expert will make the correct play and the non expert is more likely to make the incorrect play. Just a couple of errors like that in a 26 board match are likely to swing quite a few imps.

[Al_U_Card]

Here's a thought. 3NT or 4 of a major? 1 imp difference for making either. Taking four tricks on defence against both results in a multi-imp swing. BIDDING rather than defending results in a boatload of swings and lots of imps. Call it taking out insurance or whatever, the imps tend to go to the bidding side.

[keylime]

Ditto when people are stuck with the "2/1 disorder" of bidding 4M on flat opposite flat hands.