There it is. How on earth can it be possible to
solve 21 out of 156 checkers openings instead of
156 out of 156 UNLESS they have not really
solved checkers completely? This also would
seem to explain the strange comments posted
here earlier, which suggested the same thing by
misusing the term solved to mean partly-solved.

This is a misinterpretation of the results. The Chinook team proved
checkers is a draw from *the starting position* or so called "go as
you please" play. The 156 checker openings are ballots used in the 3-
move restriction style of play, where the first three plies (2 red
moves, one white move) are pre-determined. The Chinook team is not
saying that they have solved all of these, but they don't need to in
order to claim that unrestricted checkers is a draw.