When Josh Hamilton signed a five-year, $123 million contract with the Los Angeles Angels about a month ago, I did not know what to make of it. Of the available free agents, Hamilton had the best offensive season in 2012, but given his history of substance abuse and his streakiness on the field, how does one predict what Hamilton will be in 2013, never mind in 2017?

Hamilton defies comparison. On the field, I’ve always thought of him as the second-coming of Vladimir Guerrero, but while the two players share raw tools, plate discipline tendencies, and a presence that I can only think to describe as swashbuckling that always pulls my eyes to the television screen, Guerrero had a dependable greatness that Hamilton seems only to reach a few months at a time.

The seed of that comparison is their penchant to chase pitches. From 2007-2011, Guerrero swung at 44.0 percent or more of pitches thrown outside of the strike zone each season. Hamilton crossed that threshold for the first time in 2012 with a 45.4 percent O-Swing%, but he had not fallen too far short in 2011 at 41.0 percent.

Guerrero probably did not chase balls quite so frequently in his prime—FanGraphs has O-Swing% numbers that date back to 2002, and Guerrero was closer to 30 percent than 40 percent at that point—but his non-existent strike zone will always be in the first sentence of his legacy. And while Guerrero never saw a pitch he did not like, his lack of discipline belied his incredible consistency as a hitter.

Guerrero had an 11-year run from 1998-2008 in which he never fell short of 129 wRC+, and he never struck out more than 14.0 percent of his plate appearances in a season. Guerrero was a prodigy of see ball, hit ball, which manifested in a career contact rate of 67.4 percent on pitches outside the strike zone, which put him in the top-third in baseball most seasons.

In contrast, Hamilton has always struck out more than 14.0 percent of his plate appearances. For his career, he falls just short of 20.0 percent. That has not prevented him from having success, which may be why Hamilton has become more willing to chase pitches out of the strike zone. His O-Swing% has increased every season from 2007 to 2012. In 2012, he chased at nearly double his rate in 2007.

Josh Hamilton’s plate discipline by season:

Season O-Swing% O-Contact% 2007 32.5% 61.7% 2008 36.5% 62.1% 2009 37.6% 59.0% 2010 35.9% 63.1% 2011 36.7% 61.0% 2012 42.3% 49.4% Total 37.8% 58.3%

His contact rate rose in step with his increased aggressiveness prior to 2012, but when that cratered to a career-low 49.4 percent O-Contact% this season, it left Hamilton with a very peculiar distinction.

Hamilton led all qualified hitters in swing percentage on pitches out of the zone, and he also had the third-highest swing-and-miss rate on pitches out of the zone. Since 2002, only one other player has had a season in the top-10 in both categories, and he was also in the top-5 in both of them. That player is Miguel Olivo in 2011.

Hitters in the top-10 in O-Swing% and O-Miss%, 2002-2012:

Season Name O-Swing% O-Miss% O-Swing% Rank O-Miss% Rank 2012 Josh Hamilton 45.4% 47.9% 1 3 2011 Miguel Olivo 45.6% 48.8% 3 4

Let that sink in for a moment. Hamilton may be the best hitter in baseball and Olivo may be the worst. In 2011, Olivo had a wRC+ of 75, making him 25 percent worse than a league-average hitter. In 2012, Hamilton had a wRC+ of 140, making him 40 percent better than a league-average hitter. Hamilton’s batting average in 2012, .285, was 32 points higher than Olivo’s on-base percentage in 2011, .253. And yet, their two seasons share in this unusual distinction.

So what does it mean for Hamilton’s success as an Angel? I don’t know. Since both his chase rate and his contact rate were career extremes, perhaps his plate discipline will return to the more-typical numbers of a few years ago. That is probably what the Angels hoped for when they signed him. Either way, Hamilton’s profile mirrors his career and life trajectory in its strangeness. Even if he had never suffered his addictions, he would still be impossible to predict.

References & Resources

All statistics are from FanGraphs.