I'm a big fan of the computer workout and for basic mates it has worked a treat. I've just tried some of the exercises from Defending Worse Endgames and found that the AI makes terrible moves. I suspect that in all positions where the idea is to force a draw, the AI does not try to fight position. Do we know why this is? Does the computer use endgame tablebases or is this not feasible? Is this problem confined only to drawing positions?