There are many great mysteries in life. What does it all mean? Where did we come from? How did the Florida Marlins finish second in the NL East last year? The first two questions may be easier to answer.
The Marlins finished the 2009 season at 87-75, well behind the NL champion Philadelphia Phillies, but a game ahead of the Atlanta Braves and 17(!) games in front of the federal disaster area that was the 2009 New York Mets. How did it happen, and what does it say for their chances in '10?
Well, the Marlins outplayed their Pythagorean projection by about 5 games, winning 87 rather than the 82 that would have been expected of them given their total runs scored and runs allowed. The Braves, on the other hand, underplayed their projection by 5 games. In general, a team significantly over-performs by winning a lot of close games, and loses a lot of blowouts. The Marlins did get some nice bullpen performances last year, including five pitchers (Kiko Calero, Brian Sanches, Dan Meyer, Reynel Pinto and Burke Badenhop) who all threw at least 50 innings and logged ERAs under 3.50.
Was the Marlins' pen lucky or good? Well, Calero, Pinto, Meyer and Sanches all struck out more than 8 batters per nine innings, suggesting that the bullpen was staffed by pitchers who were simply good. But a closer look at the number shows some cause for concern. Calero, Meyer and closer Leo Nunez each had a BABIP (batting average on balls in play) well below the league mean of .300. BABIP is a stat with very little consistency from year to year, meaning that this year they are likely to come back up to the league mean. Additionally, the Marlins' relievers were particularly gifted at stranding runners in 2009, with five of the six previously mentioned pitchers well above the league mean (roughly 70 percent of runners stranded). The problem is that this is also a number that tends to revert the mean. So, chances are, the bullpen that closed out a lot of tight games last year will give up more hits on balls in play and will not be as fortunate at stranding runners. That's not a good recipe for bullpen success.
The Marlins had a good run in 2009, but a look inside the numbers says that they were really a just-above-.500 team that caught some breaks at the right time. Sometimes it's better to be lucky than good, but it's better to bet on the good than the lucky.
Russell Carleton is an author of Baseball Prospectus.