H. G. Muller wrote on Mon, Sep 28, 2009 07:55 PM UTC:
This might be normal statistical noise. The standard deviation in N games is 45%/sqrt(N), so for 100 games that would be 4.5%. The standard diviation in the difference of two independent 100-game matches is sqrt(2) times as large, i.e. 6.3%. So the difference between the 10-sec match and 30-sec match is more or less as one should expect when the average score for white (over an asymptotically large number of games) would be exactly equal for the two cases.
This is the problem with this kind of empirical testing; the number of games needed to get significant results is very large.