2013 Red Sox: Last year's Red Sox were a resilient bunch that compiled a 97-65 regular-season record by clipping off one consistent month after another. August 2013 was much of the same, with a 16-12 record that preceded a 16-9 mark in September. The Deadline acquisition of Jake Peavy helped out, with the right-hander going 4-1 with a 4.04 ERA down the stretch (3-1, 3.18 in August).
2012 Giants: The Giants were good all year, finishing 94-68, but they were particularly good late in the season en route to their stirring rally to a second World Series crown in three years. San Francisco went 18-11 in August and 20-10 in September/October without making any significant Deadline additions.
2011 Cardinals: St. Louis finished July with a 57-51 record, 2 1/2 games behind the Brewers in the National League Central. The Cardinals didn't completely catch fire in August, but they got it going a little bit, finishing the month 15-13, and they played well enough in September to cut what was, at one point, a 10 1/2-game deficit to six and an NL Wild Card berth. Buoyed by inspired play of Deadline acquisitions Rafael Furcal, Edwin Jackson, Octavio Dotel and Marc Rzepczynski, not to mention a few well-timed hits by third baseman David Freese, the Cardinals were able to make October history.
2010 Giants: The Giants rode the strength of their excellent pitching staff to a 92-70 record and their first title since moving to San Francisco. Oddly, August, when they went 13-15, was one of only two months in the season in which the Giants finished with a sub-.500 record. They recovered to go 19-10 in September and October to gain the momentum they'd need to storm through the playoffs and beat Texas in the Fall Classic.
2009 Yankees: The last Bronx Bombers team to win a World Series was a powerhouse all season long, winning 103 games in the regular season, and as is often the case with great clubs, August was a proving ground for how good they'd be two months later. The Yankees went 21-7, their best month of the season.
2008 Phillies: Charlie Manuel's eventual World Series darlings finished the season at 92-70, though they never quite experienced a sizzling month. But they did enough to separate themselves and gain entry into October. Their 16-13 August was their best month since a 17-12 May.
2007 Red Sox: Boston hadn't won a World Series in, well, three whole years when it rode the brilliance of Josh Beckett, Daisuke Matsuzaka, Mike Lowell and American League Rookie of the Year Dustin Pedroia to a Fall Classic sweep of the Colorado Rockies. August was a decent month for the Sox, with 16 wins and 13 losses on the way to a 96-66 regular-season record.
2006 Cardinals: This was one of Tony La Russa's most incredible managerial jobs, taking an 83-78 team all the way to World Series glory. The Cardinals staggered to that record, too, going 13-15 in August and 12-17 in September and October regular-season games before rallying when it counted the most.
2005 White Sox: Ozzie Guillen's group got off to a scintillating start, putting up a gaudy 68-35 record by the time August rolled around, so it was only natural that there would be something of a stumbling period for a club that would eventually go 11-1 in the playoffs to win its first World Series title in 88 years. The White Sox went 12-16 that August, their worst month of the season, but they rebounded to a 19-12 mark in September and October to finish the regular season at 99-63.
2004 Red Sox: The "Idiots" finished 98-64 before stunning the baseball world with their first World Series title since 1918, and August was a huge reason why. The Red Sox went 21-7 for their best singular month of the season, taking advantage of new acquisitions Orlando Cabrera, Doug Mientkiewicz and Dave Roberts to storm into October and become the first team in baseball history to come back from a 3-0 deficit in a seven-game series by pulling the trick against the Yankees in the AL Championship Series.