Here are some of the more intriguing situations that played out as Boston closed out the series with a thrilling 3-2 walk-off victory at Fenway Park, made possible in part by one decision that seemed to change everything.
Breaking the seal
The situation: Scoreless game, bottom of the fifth inning, Mark Kotsay on first base with one out, Jason Varitek at the plate.
The decision: Boston manager Terry Francona calls for Varitek, who was 2-for-12 in the series to that point, to execute a hit-and-run.
The outcome: Varitek singles through the right side, Kotsay cruises into third base, and Jacoby Ellsbury follows with a groundout to open the scoring.
The analysis: It wasn't ground-breaking stuff in terms of strategy. Pretty standard, in fact. But it was something of a concession on Francona's part to the brilliance of Angels starter John Lackey in that it was a call you typically make when you're expecting a low-scoring game.
Rest for the taxed
The situation: Down 2-0 with Lackey's pitch count approaching 90, Jed Lowrie leads off the bottom of the seventh with a rocket off the Green Monster for a single.
The decision: Angels manager Mike Scioscia stays with Lackey.
The outcome: Lackey gets Varitek out on a drive to center field and gets Ellsbury to hit into a double play.
The analysis: As good as the Angels' bullpen has been this year, it was taxed in their 12-inning victory Sunday night. And while Lackey had been touched for a pair of runs and hit hard a few times in the previous inning, he'd pitched an excellent game to that point. Pretty easy call for Scioscia.
Force him right
The situation: After replacing Red Sox starter Jon Lester to start the eighth, lefty Hideki Okajima got two quick outs to bring switch-hitting slugger Mark Teixeira to the plate.
The decision: With righty Justin Masterson ready to go in the bullpen, Francona let Okajima face Teixeira.
The outcome: After Okajima walked Teixeira, bringing Vladimir Guerrero to the plate as the potential tying run, Francona turned to Masterson. Guerrero walked, both runners advanced when Masterson appeared to cross up Varitek and threw a fastball to the backstop, and Torii Hunter stroked a game-tying single.
The analysis: Teixeira hit 26 of his 33 regular-season homers from the left side of the plate, so sticking with Okajima made all the sense in the world, as did going to Masterson with Guerrero and Hunter, both righties, coming up. Both walks were killers for Boston, but those weren't Francona's fault. The strategy was sound.
Not closing time
The situation: Tie game, runner Reggie Willits on third, one out in the top of the ninth.
The decision: Scioscia calls for his No. 9 hitter, Erick Aybar, to drop down a suicide squeeze.
The outcome: Aybar whiffs, Willits is stuck in no-man's land, and catcher Varitek tags him out with a dive after running him back toward third base. Aybar then grounds out to end the inning, and the Red Sox score in the bottom of the ninth to end the series.
The analysis: Aybar had the biggest hit of the game Sunday to extend the Angels' season, and he'd had a hit earlier in the game, but Scioscia likes to play small ball, and if Aybar had gotten the ball down, Willits would have scored easily. As often happened to the Angels in the series, lack of execution was a killer.
Mychael Urban is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.