coan.net: There are achievements that encourages sub optimal play (of even playing losing moves) under certain conditions (for instance, not taking your opponents King in Dice Chess, hoping to score "Pawn of glory" or "Deadly king" later in the game; prolonging a game of Anti Backgammon or Cloning Backgammon (by taking your opponents checkers when you shouldn't) trying to gain "Double strike" or "My three sixes"; marking up your 6 1's as a "Chance" instead of a "Six of a kind" in order to win "That was really close"; discarding full hotels, cars, houses after the second roll in order to try gaining "Five lucky dice" or "Six lucky dice"; taking the 11 instead of the 98 in Knight Fight in order to gain "Double defeat", "Path of twins" or even "A little more horse power"), so achievements for losing isn't that far off.

OTOH, a meta-rule of "you cannot gain an achievement (nor a partial achivement) one a game you did not win" would eliminate some of the sub optimal plays. And prohibit any achievement that requires one to lose.