Note that the percentages you quote are for the strong side to move, and for the checkmating almost exclusively reflect the number of immediate King captures. If the King cannot be captured in the first move, so that the weak side gets the opportunity to move, the winning chances on 8x8 have already dwindled from 27.3% to 1%. The long lines all stay within those 1%.
Note that the percentages you quote are for the strong side to move, and for the checkmating almost exclusively reflect the number of immediate King captures. If the King cannot be captured in the first move, so that the weak side gets the opportunity to move, the winning chances on 8x8 have already dwindled from 27.3% to 1%. The long lines all stay within those 1%.