Last year, the San Francisco Giants won the World Series in 5 games.  They beat the Texas Rangers, who may have had the American League's most potent offense because the Giants have the best pitching staff in baseball.  Before embarrassing the Rangers, the Giants convincingly outpitched the Philadelphia Phillies, who had and have the second best staff in baseball, and who were also supported by the most powerful lineup in the National League. 

Despite this extraordinary post-season performance, the baseball world seemed unconvinced then and remains unconvinced now that the Giants have better pitchers than everybody else.  On October 25, right before the World Series, blogger Dan Rosenheck of the New York Times won sports journalism's worst timing award when he posted: Giants Starters not as Good as Billed.  Going game by game in the five games of the World Series, the Giants starters gave up 4, 0, 4 (the Giants' only loss), 0, and 1 run respectively.  The bullpen was even better giving up 3 runs in the first game - long after the Giants batters had already decided the game with an 11 run outburst - and no more for the rest of the series.

During the hot stove season, the Giants staff began grudgingly to receive its due as perhaps the best in baseball at least until the Phillies signed Cliff Lee.  At that point, sports reporters rushed to anoint the Phillies staff as embarrasingly great - not just the best in 2011 but perhaps the finest ever.  Philadelphia Phillies: Best Pitching Rotation in Baseball History? Close Enough.  The fact that Giants ace Tim Lincecum had defeated Cliff Lee twice in the World Series apparently bounced off their collective journalistic skull.

On April 25, nearly four weeks into the season, Giants fan Scott Willis blogging as one of the three Crazy Crabbers opined:

"Giants fans were outraged when everyone and their Mother forgot about the 2010 playoffs and jumped on the Phillies bandwagon as the best in baseball. Many were incensed by the team that just beat each of these pitchers so casually being cast aside.  So far this season, the Giants have not done much to try regain the claim as the top pitching staff after their slow start."  http://www.crazycrabbers.com/p/about-crabbers.html

Whether the highlighted text was true on April 25, I cannot say, but a scant two weeks later, there is little doubt that the Giants pitchers have so far been among the very best, if not the best, in baseball this year.  Ranked by ERA, the Giants are 8th in MLB which would suggest that they have only the 8th best pitching staff.  But, the Giants pitchers have struck out more batters than any other staff.  They also have the best K/W ratio in baseball and have given up the fewest total bases and hits.  The slugging average (SA) against the Giants is the lowest in the major leagues and both SA and on-base percentage (OBP) correlate more closely with the number of runs a team scores than does batting average.  The combined SA plus OBP given up by Giants pitchers is third lowest in MLB.  At this point, you may be saying, all right Ginsberg the Giants have a good staff maybe it's even great but you haven't convinced me it's been perhaps the most effective in baseball this year.  After all, the Giants pitchers do have an ERA that's a lot higher than a lot of other staffs and their SA + OBP is not the lowest in baseball.  So, how can you argue that the Giant pitchers really are the best?

Well, there are three statistics that over time correlate most closely with pitching effectiveness.  Fewest home runs allowed, fewest walks allowed, most strikeouts.  The reason that this is so is that the quality of a team's defense and the element of luck play the smallest role in these statistics  Comparatively, when it comes to batting average and even ERA, defense and luck play bigger parts.  Depending on how good a team's shortstop is, a batter's sharply hit ground ball may be a single up the middle that scores a run or a GiDP ending an inning.  A pitcher may give up five hits in a game and toss a shut out or give up 3 runs depending on whether the hits are strung together or spaced evenly.  Defense and luck play a big part. In order to account for this, a statistic called Component Earned Run Average (ERC) has been created which supposedly takes fielding and luck out.  The Giants pitchers are third in MLB in ERC. 

I don't know how seriously to take ERC but I will say from watching lots of Giants games this year, their defense ain't great.  At short, they started the season with Miguel Tejada a 37 year-old who has definitely seen much better days.  His replacement Mike Fontenot is okay but no more.  Their should-a-been last year's gold glove centerfielder Andres Torres has been injured for most of the season and his replacements have been, like Fontenot, just adequate.  Left fielder Pat "the Bat" Burrell is not called Pat "the Glove".

They Giants have scored the fourth fewest runs in baseball. But, they are 18-16 and 1 game behind Colorado whom they just swept.  Lousy fielding, no hitting, yet they're 1 game out of first.  The Giants have the best pitching staff in baseball.