About the time Travis Wood was dousing Chicago Cubs general manager Theo Epstein with champagne Tuesday night, Epstein was explaining the prevailing theory of roster construction. "You build it for 162 (games) and you watch it play out, "Epstein said. The Cubs beat the Giants in four games with a four-run rally in the top of the ninth inning Tuesday, only the second time in playoff history a team had scored four runs in the ninth inning to win a postseason clincher.