40-Man Roster Review: Will Harris

Jeff Luhnow has a pretty good history with the waiver wire. The next player covered in this series, Will Harris, is a perfect example of evidence supporting the introductory statement. 

Before the Astros selected Harris via waivers, he had pitched for the Colorado Rockies and Arizona Diamondbacks. His tenure with the Rockies was abysmal. A couple of seasons with the Diamondbacks saw a mixed bag of results. 

In 2015, Harris broke through and excelled with a 1.90 earned run average in 71 innings of work. 

Today I pose the question: is this result sustainable? 

There are a few red flags when looking at the 2015 stat line for Harris. The first issue that I would like to mention is the discrepancy between ERA and FIP. The latter is an acronym for Fielding Independent Pitching. Fangraphs defines FIP as a "measure to what a player’s ERA would look like over a given period of time if the pitcher were to have experienced league average results on balls in play and league average timing." 

Baseball-reference credits Harris with a 3.66 mark for FIP. His 1.90 earned run average results in a 1.76 difference - that's the equivalent of nearly 2 runs per nine innings! Part of this can be attributed to a stellar defense playing. *cough* shifts *cough*

Returning to the question of sustainability, I look at Harris and Batting Average on Balls in Play (BABIP). Here, the results are perhaps even scarier. Harris' .192 BABIP is exceedingly low in comparison to the Astros' pitching staff BABIP of .285.

I took a sample of fifteen Astros pitchers from the 2015 season. These fifteen pitchers threw at least 30 innings last season. Harris' .192 BABIP was -2.65 standard deviations away from the team BABIP of .285. On a standardized mean curve, being two standard deviations away from a mean suggests that statistic occurs less than 2.5% of all cases in the long run. Therefore, I think that the BABIP Harris benefited from in 2015 is very unlikely to occur again in 2016.

Will Harris had exceptional campaign in 2015. But, his BABIP will certainly regress to the mean in 2016. Keep him in a fairly short term role in the middle innings. Nothing more, and don't expect a repeat.