The good thing about being on the bases during the postseason is that you might score a run and help your team move on toward World Series glory.
The bad thing about being on the bases during the postseason is that you might make a baserunning blunder that won't be soon forgotten.
Guerrero's teammate, Bobby Abreu, had made the most recent baserunning blunder in this ALCS, when he was victim of only the second 8-6-3 putout in postseason history. In Game 3 on Monday, Abreu doubled to center and thought about taking third. He changed his mind, and Derek Jeter took the relay from the outfield and threw to Mark Teixeira, who was alertly covering second and tagged Abreu out trying to get back to the bag.
Later that game, Torii Hunter got picked off first base by Andy Pettitte in the bottom of the third inning. Pettitte is the all-time leader in pickoffs, so his picking off Hunter was not a major shock, but still, in that situation, losing a baserunner was an egregious mistake. At the time, Guerrero was up for the Angels, with a 3-1 count.
Baserunning blunders have been especially common against the Yankees this postseason.
It happened to Nick Punto in the eighth inning in Game 3 of the AL Division Series. He rounded third base and was caught by Jorge Posada trying to dive headfirst back into the bag. That was the Twins' third baserunning gaffe in the final two games of the ALDS and took the team out of a last-gasp rally, with the Yankees only up a run at the time.
Carlos Gomez cost Minnesota a run in the fourth inning of Game 2 in the AL Division Series. Matt Tolbert delivered an apparent RBI single to right field with two outs. As Delmon Young was racing around third toward the plate, an aggressive Gomez went too far past second with an idea of taking third on a throw home. Swisher instead threw to second, where Jeter nabbed Gomez for the third out before Young could score -- the first of three baserunners Swisher has gotten on the bases in a vulnerable moment.
Michael Cuddyer was running to first base in the fifth inning of ALDS Game 3, then headed back to the bag when a liner by Jason Kubel eluded second baseman Robinson Cano and went into right field. Cuddyer reversed course and tried to reach second, but he was forced out on Swisher's throw, which again went to Jeter.
Alex Rodriguez had a baserunning blunder in the ALCS opener. Stuck in a 2-1 game at the time, Rodriguez walked with one out in the fifth before Hideki Matsui punched a line-drive hit into left-center field. As he approached third base, Rodriguez saw coach Rob Thomson waving him home. So he put his head down and rounded the bag, oblivious that Thomson had ceased waving and begun imploring Rodriguez to stop.
"Once I saw the go, I put my head down. It was my mistake," said Rodriguez, who was called out at home even though replays showed he was safe.
In Game 3 of the National League Division Series between the Cardinals and Dodgers, Yadier Molina contributed a running error. On a night when Dodgers starter Vicente Padilla didn't need much help, Molina still gave it to him in the seventh inning. The Cardinals catcher inexplicably tried to advance to third on a ground ball to shortstop Rafael Furcal by Mark DeRosa and was thrown out for the second out of the inning.
The next hitter, shortstop Brendan Ryan, flied out to center field for the final out and just like that, the best night of Padilla's career was complete.
Mark Newman is enterprise editor of MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.