Now in the midst of his eighth season with a full-time starting gig, Clay Buchholz remains an enigma.

He’s a two-time All-Star and twice the owner of single-season ERA below three runs per nine. He’s also twice finished a season with an ERA over five and four times failed to top 170 innings four times since becoming a rotaion regular.

At first glance, he looks like much the same guy this season (1-2, 4.84 ERA) as the pitcher who last year threw 170.1 innings of 5.34 ERA ball — but there’s more to the story.

Buchholz’s 4.84 ERA is certainly poor, but it belies how well the right-hander has been pitching aside from his nine-run blowup on April 12. He has played much better than his ERA suggests, with the discrepancy between play and results largely due to BABIP, or batting average on balls in play. Opponents are hitting at a .371 clip when they put balls in play against Buchholz this season, well above the league average of about .300 and even further above his career number of .287.


While this could suggest Buchholz is giving up a ton of good contact (more on that later), more likely he’s been the victim of a small sample size and bad luck. Buchholz has been hit for 15.9 percent liners, 55.6 percent grounders and 28.6 percent flies for a batted ball profile that would typically result in a better-than-average BABIP number, so fewer guys should reach base in the future. The classification of batted balls can be subjective — the line between a soft liner and a hard fly can be rather gray — but there’s enough here that the low liner rate is verging on a trend.

Further supporting the poor luck hypothesis, according to a Fangraphs report, opponents are hitting .367 on grounders against Buchholz this season (against a league average of .239) despite a strong defensive infield of Pablo Sandoval, Xander Bogaerts and Dustin Pedroia.

The stats less informed by luck paint an even rosier picture of Buchholz’s performance so far. His strikeout rate is a whopping 11.69 K’s per nine innings, a full four strikeouts better than his career rate. While it’s such an outlier from his career numbers that he’s not likely to maintain this pace, Buchholz backs up the improvement with an 11.1 swinging strike rate, so some of the Ks are here to stay.


His improvement in this area would seem to come from his inducing swings on 35.8 percent of his pitches outside the zone (against a career 29.6 percent rate) and allowing contact on just 62.8 percent of those pitches, better than three points below his career rate. It’s no coincidence that Buchholz’s outside swing percentage (26.2) and outside contact percentage (81.8) were his worst in that April 12 blowup. Should Buchholz keep limiting contact and getting batters to chase, he should see better results.

Buchholz has also averaged a speed difference of nearly 13 mph between his fastball and changeup this season, which generally improves the success of both pitches. He averaged an already strong 9.7 mph difference last season.

Also helping Buchholz this season is his low walk rate, as he’s issuing a career-low 2.82 free passes per nine innings. He’s thrown strikes and balls at a ratio of nearly 2:1, which backs up these results. It’s possible he inches closer to his 3.32 career BB/9 as the season wears on, but given his posting sub-3 BB/9 rates the last two seasons, there’s reason for optimism.

Buchholz’s start hasn’t look so hot as a whole, but on a per-pitch basis, he’s doing the things he needs to in order to keep runners off the base paths. If he keeps it up, the wins will come.