Walk off double with bases loaded when only one run is required to score, i.e., the batter should not get to second when the runner on third is forced home on the first base advance to win the game.
http://www.ootpdevelopments.com/boar...k-off-hit.html
Note: A ground-rule double is scored a single per the rule book as the game ends when the first runner is forced home except for in the case of a home run:
see:
(c) If the home team scores the winning run in its half of the ninth inning (or its half of an extra inning after a tie), the game ends immediately when the winning run is scored. EXCEPTION: If the last batter in a game hits a home run out of the playing field, the batter-runner and all runners on base are permitted to score, in accordance with the base-running rules, and the game ends when the batter-runner touches home plate.