aaru: At some point, although absolute proof may still be out of reach, it is more reasonable to conclude that cheating has taken place. On another site, I analyzed several players' matches. In one case, I found at least 3 lengthy (21-point) matches where the player had 0 moves marked very bad, 0 moves marked bad, and just 1 marked doubtful--at gnubg's default settings.
If I wanted to play against gnubg, I could do that without coming here to BK.