The Giants' World Series win was a pretty unlikely one, no question. Prior to the season, I don't think anyone had them favored to win their division. Even three months ago, it looked pretty unlikely. But thanks to an epic collapse by the San Diego Padres, the Giants won their division and managed to win three consecutive series as the underdog on their way to a championship.
The Giants had Barry Bonds, who put up the biggest numbers in the last 40 years, on their roster for 15 seasons, and they had very little playoff success. This season, they succeeded despite having the biggest mishmash of retreads you could possibly imagine - only one hitter in the final World Series game was homegrown, Buster Posey, and the Giants were so reluctant to play him this season that they blew $4M re-signing Bengie Molina to play ahead of him; six of their remaining seven regulars aren't even under contract for next season. The stars aligned for the Giants this season, and many of their retreads hit career highs; I can't imagine GM Brian Sabean expected that outcome.
No one can deny that the Giants have a quality pitching staff, but it almost wasn't. After drafting Matt Cain 21st in 2002, the Giants intentionally gave away their first and second (and sometimes third) round draft picks. They claimed - and I kid you not - that early draft picks were overvalued and that they could get the same caliber of picks in the 3rd round or later. I don't need to remind you that Tim Lincecum, Buster Posey and Madison Bumgarner were all early first round draft picks and contributed greatly to the team's success this season. The only reason that the Giants didn't give them away too is that MLB rules forbid it - any team that finishes in the bottom 15 of the league, as the Giants did for four consecutive seasons, can't give away its first round pick. The league doesn't want teams doing anything colossally stupid, and that paternalism is what saved the Giants.
Some people will say that the World Series win proves Brian Sabean's skill as a general manager - you don't win if you're not good. But as anyone who lived in San Francisco through the dot.com boom can attest, there are a lot of people whose success comes from being in the right place at the right time. Giants fans should relish their team's victory - but they should also demand new management that needs a little less luck to win. Otherwise, we could be waiting another 56 years for the next World Series ring.