A quick follow-up to the previous post on Brandon Belt's 0-for-8, five-strikeout game. I briefly mentioned WPA in that post -- win probability added, which Baseball-Reference.com explains as "Given average teams, this is the change in probability caused by each batter in this game." This brings context into each plate appearance: Striking out with the bases loaded in a tie game hurts more than doing it in a five-run game.
So, the worst single-game WPA for games that Baseball-Reference has play-by-play data for belongs to ... drum roll ... Juan Rivera, playing for the Yankees against the Tigers on June 1, 2003. Rivera would go 0-for-6 with a walk and was credited with -.820 WPA. Here's what happened:
Second inning, 0-0, runners at first and third, one out: Rivera grounds into a double play.
Fourth inning, Yankees up 4-1, runner on second, one out: Fly out to center.
Sixth inning, Yankees up 7-6: Grounds out leading off inning.
Eighth inning, 8-8, nobody on, two outs: Grounds out.
10th inning, 8-8, bases loaded, one out: Grounds into a double play.
13th inning, 8-8, bases empty, two outs: Walk.
15th inning, 8-8, runners at first and third, one out: Grounds into another double play.
Three killer double plays, including two in extra innings. That's how you get the worse game ever. The kicker here, however: The Yankees actually won the game 10-9 (in our previous list, with the exception of Chris Davis, all the other players lost their game). Alfonso Soriano and Jorge Posada hit home runs in the 17th inning and Juan Acevedo relieved David Wells (who had pitched 5.2 innings in relief) for the final out to get the save.