So have the Giants just been lucky? Or have they, contra conventional wisdom, somehow figured out the postseason?

According to Joe Sheehan, who authors an influential baseball newsletter, the postseason is still “95 percent a crapshoot. Teams can’t build for the postseason since they don’t even know if they’re going to make it.”

But Sheehan acknowledged that the formula for regular season success—a deep, versatile roster able to overcome the slumps and injuries that occur during the grind of 162 games—is less relevant in the playoffs.

“Teams like the Washington Nationals, who won 96 games, were helped by having a deep starting rotation,” he said. “But in a five or seven-game playoff series, having a good fifth starter doesn’t give you an advantage since he might not be used at all.”

The Giants, whose own starting rotation struggled with injury and ineffectiveness, won just 88 games this season and barely squeaked into the playoffs. But once they qualified, San Francisco cashed in a major advantage: a deep, skillful bullpen and a manager, Bruce Bochy, with the imagination and ability to get the most out of it.

According to Wendy Thurm, a baseball writer and analyst, relief pitchers prefer to have set roles: game situations in which they can reasonably expect to appear. Bochy, however, is willing to use his relievers in a variety of situations throughout a series.

“Bochy isn’t a slave to orthodoxy,” Thurm said. “He understands when high-leverage situations—the moments when games are won or lost—occur, and he makes sure he has the right guy out there at that time.”

Consider the fifth game of the National League Championship Series. In the top of the ninth inning, Bochy brought in Santiago Casilla, his closer, to preserve a 3-3 tie against the St. Louis Cardinals. Casilla immediately got into trouble, and before long the Cardinals loaded the bases. But rather than leave Casilla in, as convention would dictate, Bochy replaced him with Jeremy Affeldt, who retired the side without giving up a run.

The move paid off. In the bottom of the ninth, Cardinals manager Mike Matheny decided not to use his closer, Trevor Rosenthal, despite the presence of a high-leverage situation. Instead, he brought in Michael Wacha, a starting pitcher who hadn’t appeared in a game since September 26. The rusty Wacha was wild and ineffective, and ultimately gave up the home run that cost the Cardinals the game and the series.

Afterwards, Matheny defended his decision to leave Rosenthal in the bullpen by citing baseball orthodoxy. “We can’t bring him in, in a tie-game situation. We’re on the road,” he said.

Bochy’s willingness to subvert convention stems in part from his bullpen’s remarkable continuity. Four of the team’s key relievers—Jeremy Affeldt, Javier Lopez, Sergio Romo, and Casilla—were members of both the 2010 and 2012 World Series winning teams, and have remained with San Francisco despite occasional regular season struggles. In 2012, Bochy named Casilla as his closer following Brian Wilson’s injury, but when Casilla struggled Bochy replaced him with Romo. Romo then held the closer’s job until his own struggles this summer; fittingly, Bochy replaced him with Casilla. Both relievers have generally pitched well this postseason.