This blog provides supplementary thoughts and ideas to the site. If you haven't seen the main site, there is a lot there including the Martel and Rodwell interviews, photos, and articles. This blog is focused on advancing bridge theory by discussing the application of new ideas. All original content is copyright 2009 Glen Ashton.

Thursday, July 10, 2008

Mike Bell, in a comment to the previous entry, asks "These are all good things to be aiming for, but I don't see why you think they are (much) more significant at MPs than at IMPs"

Let's say we have a hand, where there is:
5% for a 100% slam
5% for a 60% slam
70% - game only
20% - game only, but trying for slam will stop overtrick

At IMPs it is clear a plus chance to try for slam - the overtrick is costing an IMP, while the slams are delivering big IMPs

At Pairs (with matchpoint scoring) it is a minus chance to try for slam - the slam when making delivers a good board, but the lost overtrick costs a bad board, and occurs more often.

At Pairs there are far more of these overtrick costing situations than at IMPs.

At Pairs the decision to compete or not for a partscore is more important - at IMPs being +100 for defending 3C or being +110 for being 2S is equal. At matchpoints, that mere 10 points is key. Getting to the "par spot" quickly gives the opponents less information to judge these important decisions at Pairs.

1Beach is getting there quickly. Part of this includes the "Pressure Bidding" style that is successful at IMPs, but 1Beach is more than this - it is the non-disclosure part that also works often at Pairs.

Even for pressure bidding, at IMPs one can handle it by:
- take the # if offered by the opponents
- bid a game - it only needs to make a decent % of the time

At Pairs, pressure bidding at Pairs means:
- taking the # could be wrong, if that # is less than the higher paying value of making your contract
- bidding odds against games are wrong

The first step in using a 1Beach approach is to watch how much you and/or your opponents give out in standard sequences. Say 1H-1NT(forcing);-2D-3H(limit raise);-4H - compared to 1H-4H or 2H-4H - when your slower revealing sequences come up in play, watch how they help the opponents. When the slower revealing sequences are used against you, see how they help you pick the opening lead and subsequent defense. The results are amazing.


  • At 6:42 AM, Blogger MickyB said…

    Ok, sure, a system that is poor for bidding slams is likely to be more suited to MPs than IMPs.

    Other than that, I remain unconvinced. Yes, you will find you gain more often at MPs from 1beach sequences, where 4th seat misguesses or the lack of disclosure causes a trick to slip through on defence; But that's simply because every board makes a difference at MPs, whereas at IMPs there are a fair proportion of boards where it would be very difficult to lose more than an IMP or two.

    On the boards where you can make a difference, 1beach has the potential to make a big difference. A double part-score swing, or a penalty trying to prevent a double part-score swing, is worth a fair bit; A game let through on a low-disclosure auction is worth even more, and far more than any one board could be at matchpoints.

    Of course, there will be times when it's clearly right to use the slam tools available at IMPs, where the odds are as you have given in your example - but if we are looking at 1H-P and you are considering whether to bid 4H or look for a slam that will be cold 5% of the time, it's still clear to just blast game - maybe 3% of the time, *game* won't be cold but they'll let it through now, and another 5% of the time they'll misguess whether to bid 4S or not, and another 2% of the time investigating the good slam might lead you to a poor slam.

    There are three main conditions you could consider changing system by -


    I still think that scoring is the least significant of these, and position the most significant.


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