Aaron Sanchez has evolved considerably since debuting two summers ago. He still generates all kinds of ground balls while limiting hits, but he now throws more off-speed stuff and has added muscle in the hopes of becoming more durable.
That’s not all that’s changed since 2014. Sanchez now faces a much different set of hitters, a group that puts many of his adjustments to the test because it skews heavily to the left.
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A right-hander with a low arm slot, Sanchez has dominated right-handed batters since 2014. They have just a .388 OPS against him with zero homers in 285 plate appearances, while lefties have a .773 OPS with 12 homers in 292 plate appearances.
That’s a pretty striking difference, one that opposing managers are taking into account when setting lineups. When Sanchez pitched in relief, the Blue Jays controlled who he faced. Now that he’s a starter, the decision-making power shifts to the opposition. It’s no surprise that Sanchez has faced more and more left-handed hitters since 2014.
| Year | MLB average % of PA vs. LHB | Sanchez PA vs. RHB | Sanchez PA vs. LHB | % of Sanchez PA vs. LHB |
|---|---|---|---|---|
| 2014 | 44% | 75 | 46 | 38% |
| 2015 | 43% | 178 | 202 | 53% |
| 2016 | 41% | 32 | 44 | 58% |
Really it’s not that surprising. Opposing managers see that Sanchez posts worse strikeout, walk and homer numbers against lefties, and stack their lineups accordingly. It’s not a coincidence that part-time, lefty-swinging players like Jackie Bradley Jr., Marco Hernandez and Hank Conger have all started against Sanchez.
It’s early, but the lefty-heavy lineups aren’t scoring against Sanchez this year. He has a 1.35 ERA through three starts thanks in large part to his work against lefties. While they have two home runs and six walks, they’re hitting just .158 with a .615 OPS.
Sanchez’s pitch selection helps explain his success. Mixing in curves and changeups has been essential for a pitcher who won a rotation spot thanks in part to his improved secondary stuff.
All told, he still throws fastballs 76 per cent of the time — more frequently than any other American League starter. But the fastball-heavy pitch mix that’s so effective against right-handed batters wouldn’t work against lefties, so Sanchez has had to adjust, relying on secondary stuff nearly twice as frequently against lefties.
LISTEN: Talking Aaron Sanchez and Marcus Stroman on the At the Letters podcast
So far Sanchez’s pitch selection has been unpredictable from start to start. Catcher Russell Martin has stayed flexible, calling for what’s working.
Sanchez relied heavily on the change in his season debut against the Rays, generating four swings and misses, all against lefties. That’s evidence that the pitch can be as effective as the curve, which happened to be Sanchez’s best secondary offering against the Yankees’ lefty bats. Then, while facing the Red Sox in his third start of the season, he threw more fastballs and just one changeup, an approach reminiscent of late last year, when he just about stopped using his change coming out of the bullpen.
When the Athletics face Sanchez Friday, expect the tests against lefties to continue. By starting Chris Coghlan, Stephen Vogt and Yonder Alonso, Oakland could field a lineup featuring just three right-handed hitters.
The way Sanchez has pitched, it’s clear he belongs in the starting rotation. It’s just as clear that he’ll need continued success against lefties to stay there.
