By Chinook, actually. The computer science Jonathan Schaeffer became obsessed with solving checkers, because it was the only way to prove that Chinook could've

By Chinook, actually. The computer science Jonathan Schaeffer became obsessed with solving checkers, because it was the only way to prove that Chinook could've beaten Tinsley in a fair game (as Tinsley passed away before Chinook could defeat him on the board).