What’s Going on with Hector Santiago?

Hector Santiago has historically been the type of pitcher I won’t roster in fantasy. The lefty has a track record of smashing his ERA estimators (3.51 ERA for his career compared to a 4.51 FIP, 4.67 xFIP and 4.26 SIERA) with underwhelming strikeout rates, mediocre stuff and below average control. No, I don’t blindly regress a pitcher like Santiago to his ERA estimators. It appears some skill or skills he possesses allows him to post an ERA that’s better than them. That said, I’m usually leery of the gap between the ERA and the ERA estimators closing, and with the bulk of the lefty’s fantasy relevance tied to posting a helpful ERA, any slippage would cripple his value. This isn’t the same Santiago anymore, though, and I now roster him in all three fantasy leagues I’m in this year.

The 28-year-old southpaw has made three starts spanning 20.2 innings — pitching at least six innings in each of his turns –in which he’s tallied a 24.7% strikeout rate, 7.4% walk rate and 2.61 ERA. As usual, his ERA estimators (3.87 FIP, 3.72 xFIP and 3.47 SIERA) don’t line up with his ERA, but that’s the norm at this point for the veteran pitcher. A small sample size caveat is obviously in order, but Santiago is pitching better this year than we’ve previously seen. He’s worked as a starter and reliever in his career, and prior to this season he’s made 83 starts. In those starts, he owns a 21.2% strikeout rate, 10.1% walk rate, 32.7% ground ball rate and 8.0% SwStr% with a 3.64 ERA, 4.54 FIP, 4.72 xFIP and 4.34 SIERA.

This year, the lefty has bumped his strikeout rate up by 3.5% while shaving 2.7% off his walk rate. Those are huge changes, and his strikeout rate is supported by an eye-popping jump to his swinging strike rate of four percent. Santiago’s 12.0% swinging strike rate easily bests the league average mark of 10.3% in 2016, too. When he’s not missing bats at a higher clip, he’s inducing more worm burners. Santiago has tallied a 47.3% ground ball rate this year that’s up an astonishing 17.4% from last year (29.9%).

His favorable gain in ground ball rate hasn’t impacted his ability to coax infield fly balls at a high clip. As a starter prior to this year, Santiago owned a 12.2% infield fly ball rate. This year, that mark sits at 12.5%. Pop ups are basically free outs, and a whopping 28.4% of the batters he’s faced this year have punched out or popped the ball up. Last season, essentially a quarter of the batters he faced — 24.87% to be exact — struck out or popped the ball up. It’s likely his infield fly ball rate is one input that’s helped Santiago best his ERA estimators annually since it reduces his BABIP allowed. When you pair his punch outs and pop ups together, that’s a lot of outs that aren’t reliant on the vagaries of batted ball luck.

Three promising starts alone aren’t enough to move the needle a ton on Santiago’s stock, but there are other reasons for optimism about his hot start being more than a flash in the pan. The lefty is pumping out blazing fastballs this season. His four-seam fastball is averaging 92.97 mph in the regular season, per Brooks Baseball. Last year, it averaged just 90.90 mph, and he hasn’t surpassed an average velo of 92 mph since 2013. His average four-seam fastball velocity ranks 44th out of 107 among those thrown a minimum of 50 times, according to Baseball Prospectus. And to add further perspective, it’s a smidge faster than David Price’s thus far this year. The pitch ranks ninth in whiff/swing percentage and has a 46% ground ball rate on balls put in play. He’s thrown his four-seam fastball 63.72% of the time through three starts and has a drool-inducing 12.65% whiff rate on the pitch. The lefty hurler’s new found cheddar is a top-shelf weapon in the early going, and you might be asking yourself where the heck it came from.

The Los Angeles Times featured some interesting tidbits following Santiago’s dominant start against the White Sox on Monday night. According to the linked article written by Pedro Moura, Santiago made three major adjustments in the offseason:

He began to power lift to his maximum regularly. He set his mind to pitch like a reliever at all times, never holding back to ensure he could last. And he started a poststart regimen in which he works out immediately after he exits the mound, building up stamina so he can hold the velocity.

Now that’s an explanation that supports his velocity blowing up this year. Will he wear down during the dog days of the summer? It’s possible. No one can definitively conclude he will or won’t be able to maintain hit current max-effort approach over the course of a full year, but for now, it explains his early season results and gains.

Santiago’s fastball is his best bat-missing pitch so far this year, but it’s not the only option he has to avoid contact. The lefty’s changeup has a 10.89% whiff rate, the slider sits at a 10.81% whiff rate and his cutter has a 12% whiff rate. The whiff rates on his changeup and slider are unexciting relative to other changeups and sliders, but with four pitches earning a whiff rate north of 10%, he has the tools in his tool belt necessary to continue to strikeout batters at a rate north of the league average — assuming he retains most or all of his four-seam fastball velocity gains. I’m not quite ready to declare him a top-50 starting pitcher going forward, but he’s right on the cusp of that lofty ranking and worth speculating on in even the shallowest of leagues.