October 10, 2011
Hellickson's BABIP: Lucky or Sustainable?
Since the season has ended, many have been quick to point at the Rookie of the Year Candidate and his historically low .224 batting average on balls in play. Hellickson’s BABIP is the seventh lowest total since the 1980 season and the lowest since 1990. Only Jeff Robinson, Tom Browning, Pascual Perez, Tom Seaver, Dan Petry, and Jerry Ujdur have had BABIP’s lower than Hellickson’s in a season large enough to qualify for the ERA title. Before Hellickson’s result this season, Chris Young is the only other pitcher in this millennium with a BABIP this low—.230 in 2006.
Nobody expects Hellickson to be able to post such a low BABIP in 2012 as we know pitchers cannot control everything that follows their release of the baseball. What we do not know is how much Hellickson’s BABIP will increase. If we look at the six pitchers who had lower BABIPs than since Hellickson since 1980, we see mixed results:
Overall, the numbers are not terribly encouraging. Tom Browning had the smallest amount of regression while Tom Terrific regressed right passed the mean without collecting $200. The average BABIP for these six pitchers was 62 points higher in the following season, which is a scary thought for those in keeper leagues that are protecting Hellickson and something to keep in mind as making your 2012 draft plans. Six pitchers are a ridiculously small sample size to look at, but it at least gives us a starting point for a range of expectations for where a pitcher with an extremely low BABIP could regress to the following season. If we expand the pool to look at pitchers since the 2000 season who have had BABIP’s below .260, we get a larger sample size to look at:
That group of pitchers contains as many hard throwers as it does soft-tossers; BABIP regression does not discriminate. Only lefties Zito and Moyer saw their BABIP fortunes improve the season after a fortunate season while 15 others saw their BABIP rise by less than 20 points.
The correlation between BABIP and the regression from one season to the next is not terribly consistent. In fact, the correlation coefficient is only -0.37. The following graph shows this relationship.
One thing that should help temper Hellickson’s regression is the Tampa Bay Rays’ team defense, which continually grades out as the best in baseball. Manager Joe Maddon implements more defensive shifts than any other manager in baseball, and that is one reason why only James Shields has had a BABIP over .290 as a Rays pitcher the last few seasons. In 2011, the pitching staff’s BABIP was just .265, which helps frame Hellickson’s numbers in a better light rather than just chalking it up to extreme good fortune. If he were pitching for the White Sox or Twins, teams that each had a team BABIP over .300, owners would rightly be concerned for 2012.
The fact that Hellickson has a strong team defense behind him and has shown a strong ability to generate harmless infield fly balls should help keep his regression under control in 2012 and at a more palatable level than what others before him have experienced the season after their BABIP fortunes.