To very little fanfare this offseason, the Oakland Athletics acquired Liam Hendriks from the Toronto Blue Jays in exchange for Jesse Chavez. Hendriks was once a below-average starter for the Minnesota Twins and later for the Blue Jays, posting a 5.95 ERA across 171 innings from 2011-2014. Last season, the Blue Jays moved Hendricks to the bullpen and he excelled with a 2.92 ERA across 64.2 innings out of the pen. Like many starters who move to the pen, Hendriks saw the typical velocity jump. In 2015, Hendriks’ average fastball velocity was 94.5 MPH a significant improvement over his highest average when starting, which was 91.3 in 2014. So far in 2016, Hendriks has not been great, as he has posted an ERA of 8.53 across his 12.2 innings. Hendriks’ K/9 and BB/9 have been excellent at 10.66 and 0.71 respectively, but he has faced a bit of bad luck in the longball department allowing 1.42 HR/9 much higher than 2015 numbers as well as an insane BABIP figure of 0.512.
Once Hendriks’s luck begins to change, he should be expected to return to his 2015 form, making him a well above average releiver and weapon for the Athletics, who have performed better than expected in 2016. Looking back on his 2015 pitch mix, Hendriks could make a simple change that could lead to even more success.
Unsurprisingly, Hendriks was much better against righties than lefties in 2015. Righties posted a .219 wOBA while lefties were at .324. This is a typical phenomenon for many pitchers, especially relievers who can typically be shielded from facing opposite-handed hitters. However, Hendriks’ pitch mix reveals something he could easily change. In 2015, Hendriks was essentially a three-pitch pitcher throwing mostly fastballs, sinkers, and sliders.
Hendriks has also used a change and a curve, but both pitches were thrown less than 5 percent of the time. Looking at the numbers, it is obvious that his sinker is his worst pitch, with an insane high batting average against as well as a high ISO. For comparison, hitters against his slider hit with the power of Brandon Moss, who hit 19 HRs in 2015. It is evident that the sinker is his worst pitch and surprisingly, Hendriks throws this pitch even more frequently against lefties.
The above table shows the same figures as the previous table, but only against lefties. Despite the massive difference in his wOBA against lefties and righties, two of his three most heavily used pitches actually showed slight improvements facing lefties in 2015. The most interesting fact about it though is that Hendriks’ sinker got hit even harder by lefites seeing a jump in ISO of 70 points. Left-handed hitters in 2015 hit Hendriks’s sinker like Paul Goldschmidt or Yoenis Cespedes.
Although it truly may not be this simple, a easy thing for Hendriks to try to fix is to stop throwing his sinker so much. His fastball and slider are above-average pitches, and against lefties could even be considered elite pitches. His sinker is far from elite, and despite this extremely obvious fact, he throws the pitch even more frequently when facing lefties. If Hendriks wants to take the next step and develop into the elite reliever he has shown the potential to be, it may be time for him to ditch his sinker, or at least stop making it his most frequently used pitch against lefties.