MINTS ON AUCTION BRIDGE

Sun (Auckland), Volume III, Issue 810, 2 November 1929, Page 30

MINTS ON AUCTION BRIDGE

A Bridge Player's Statistics (II)

(Written for THE SL'S by “Caliban.”— Copyright in Sciv Zealand.) IN MY ARTICLE last week I reproduced, in tabular form, Trinculo’s nummary of the results of throe hundred consecutive rubbers. The comments on this table which suggest themselves are as follows: (1) Trinculo *s ‘ * expectation’ * (which he communicated to me before any of these rubbers were played)—that he would win, on an average, fifty-seven out of a hundred—proved to be almost comically accurate. He won, in fact, 160 out of three hundred, or 56.3 per cent. If every player learnt to assess his capacities as accurately as this, we should not hear so much about ‘‘luck.” (I here were several ‘‘runs ’ of good and bad luck experienced during the course of these rubbers. Thus, Trinculo went off with a ‘‘bang,’* winning forty-three out ol his first seventy, and standing, at the end of them, 7391 points to the good—an average of over one hundred points per rubber. This was obviously to-» good to last. By contrast, he lost thirtytwo rubbers o't of sixty (betwe. u the 211th and 270th), and was 5533 points down on the scries, or an average of over ninety points per rubber. Players who do not record, ami review, their results taken as a whole are apt to draw quite misleading conclusions from runs of luck such as these. (3) The longest sequence of winning rubbers was e*ight (three times); the longest sequence of losing rubbers, six. (4) The distribution of rubbers won and lost according to their size is extremely interesting. It is as follows:

This table t hr.:t certain amount of light on Trinculo *s methods; it shows that the rubbers he loses are substantially larger, on the average, than the rubbers.he wins. Of the three hundred rubbers here analysed, hia winning rubbers average 383 points; his losing rubbers 401. points. What is the explanation? It is, I think, fairly obvious: that Trinculo plays a more dogged defensive game than do most of those at his table. ‘ ‘ Every call I make, y ’he tells me, “is based on a calculation of chances; if my expectation of loss, ou a call made to save the rubber, i< less than my expectation of loss if I don’t'make it, then it pays me, in the long run, to go ahead. I lose, I admit,’’ a fair proportion of good-sized rubbers —but look at all the rubbers I save. His statistics, I think, bear out his contention that his policy is a sound one. Confirmation of this explanation is to be found in the fact that, of the rubbers won by Trinculo, twenty-three were rubbers of 350 to 400 points, whereas less than half that number of such rubbers .were lost. Now these, in the main, are the rubbers, w-on, perhaps, in a couple of hands or so, which indifferent players allow to go by default—because they lack either the courage to take risks, or the ability to evaluate them. Out of 300 rubbers, Trinculo won 38 more than ho lost; as he rightly says, 38 times 256 ia 9500 points, and a surplus of 9500 points gives one plenty of margin for flag-flying.

{Size of i K libbers Won. 1 Rubbers Lost. Rubber; ! Number j . ’erceu t.age|j Number Percentage $00 and Over ! 7 1 4.1 i 9 6.0 700—790 7 4.1 7 600—600 9 5.3 1 6 4.6 500— o99 16 | 0.5 i 14 10.7 450 —490 15 | 8.9 j 14 10.7 Total 450 and.over 1 54 31.0 i 50 3S.2 400—409 16 | 9.5 1 12 9.1 350—390 i 05 | 13.0 1 11 8.4 300—340 -’0 1 11.8 1 4 10.7 200 —290 21 | 12.4 i 17 18.0 100—190 20 11.8 ! 13 9.9 Under 100 1 15 1 8.9 14 10.7 Total under 450 II 1 115 | 6S.1 j i 81 61.8 Total . . i 109 100.0 i 181 100.0