[Zelandakh]

An interesting statistic that might be nice to add to that would be the percentage of individual plays that were worse than DD. So declarer has to choose 24 cards in a hand and analyse each of them to produce a percentage; the same for the 12 choices each defender makes. The advantage of this number would be that it is less affected by the level of the opposition. Not completely unaffected, since weaker opponents will make the best plays easier to find, but at least their direct mistakes do not get factored in.

[Wayne_LV]

Disappointing number of votes.

Time consuming as it was, I did a comparison of 500 IMP boards played this month by myself and 2 regular partners.

RESULTS:

WE DECLARED:

No. Boards............... 237
% Boards................ 47.4%
Average GiB DD..... 9.40 tricks
Average Actual......... 9.39 tricks
% = or Better......... 70.5%
IMP/Bd................... .58


WE DEFENDED:

No. Boards................ 263
% Boards................. 52.6%
Average GiB DD...... 3.71 tricks
Average Actual.......... 4.10 tricks
% = or Better........... 82.9%
IMP/Bd.................... .27



OVERALL:

No. Boards...............500
% Boards................100%
Average GiB DD..... 6.40 tricks
Average Actual......... 6.61 tricks
% = or Better.......... 77.0%
IMP/Bd................... .41


Is this good or bad? My feeling is there is room for improvement. I think a consistent average of 80-85% should be expected by Advanced pairs and real Experts should hit 90% +.

Note that the expected Average GiB DD is 6.50 or half the possible tricks.

[inquiry]

Wayne, since you are willing to publish your stats, I thought it would be useful to throw a larger sample up for you. This was not painful (actually easy) using the database method I described in the Excel trick threat and Double dummy solver.

I looked at 1538 hands you played on-line still available in myhands. I threw out 9 hands you played with random partners, leaving just your normal two partners for a total of 1529 hands. On these hands your side averaged +0.77 imps over 675 hands as declarer, but -0.001 imps over 689 hands as defenders (that I rounded up!). The average imps per hand over the total 0.38 imps over 1364 total imp hands.

The matchpoint results were similar. As declaring side, you averaged 0.52% over 82 hands, and as defender, 0.50 over 86 hands. The overall average was 0.51 over 168 hands.

But what you seem to be interested in is double dummy play. Here is the data from Double Dummy solver for all 1529 hands....




From this data, you see your partnership play was double dummy 74% of the time, and your double dummy defense was just slightly worse. Your opponents had very similar numbers. You seem to not be doubling often enough, and I would be concerned about how frequently you miss game (Since most hands are imps, you want to bid them aggressively) and this is supported by your very low "overbid" percentage. Your missed slam is also a bit high. Also your missed "sacrifices" seem a higher than normal (compare to your opponents). So I suggest a step up in your aggressiveness for little while and see if that improves your results (note I didn't look at any hands, so I may be full of crap).

All in all, your numbers here are not bad. I think between 75% and 80% for double dummy is about right. Your numbers for this and your opponents for that matter match the double dummy results for all the JEC opponents in the past month (see post 19) and most of them are at least high advanced or better (there are some exceptions). The worse your opponents, the higher your double dummy results will be because even if you screw up, they throw tricks back to you. The better your opponents, the worse your Double dummy results will be becase they are not giving you extra tricks as often to make up for your mistakes.