You may be surprised to hear that Phillies closer Jeanmar Gomez is leading all of baseball right now with 17 saves. It’s surprising because A) Who thought the Phillies would even have 17 games to be saved this early in the season, and B) Who even knew who Jeanmar Gomez was before the season.

Since beating out David Hernandez for the job back in April, Gomez has blown just one save and led a surprisingly good Phillies bullpen. It all sounds good on paper, but if you’ve watched him pitch, he doesn’t look like an elite closer. The strikeouts we’re accustomed to seeing from our elite closers just aren’t there.

There’s Jeanmar Gomez below Twins fill-in closer Kevin Jepsen. Phillies set-up man Hector Neris would come in at 7th, slotting between Colome and Casilla with an 11.71 K/9.

This isn’t a post about how Gomez changed one little thing and suddenly became an amazing closer. He’s been good, if not great, since he was traded from the Indians to the Pirates 2013. And he’s done it more or less the same way since then: pitch to contact, generate a ton of groundballs with his great sinker, and limit home runs. He’s got a sinker/slider/changeup repertoire that’s remained pretty constant since 2013, but I noticed something interesting about his changeup usage this year. Or rather how he’s using it.

Gomez is relying more on his off-speed and breaking stuff this year, and in particular he’s revisiting that changeup after a one year lull. By Fangraphs’ Pitch Values metric, the change and the slider have been his most valuable pitches on a per 100 pitch basis this season. The change has always been plus pitch, but if you go back to 2014 when he was relying on the change/slider at about the same rate, neither pitch was close to as effective as they are now. The slider actually graded out negatively.

To recap: 2014 Gomez decided to try out upping his change (23.4%) and slider usage (14.5%) with mediocre results. 2015 Gomez abandoned that plan and instead relied on his sinker more with pretty good results. 2016 Gomez finds his 2014 in the clubhouse recycling bin and decides to up his change (23.4% thus far) and slider usage (15% thus far) again, with excellent results.

I went to check things out on PITCHf/x and Brooks Baseball, and saw that the velocity on both pitches was actually down a tick on the change and by 2 MPH on the slider. I then looked into where he was locating his pitches and found something. Here’s the locations of Gomez’ slider in 2014 vs. 2016.

In 2014 that slider is more elevated and catching a ton of the middle of the zone. In 2016 it’s consistently located low and away to righties and down and in to lefties.

Here’s the locations of Gomez’ changeup in 2014 vs. 2016.

In 2014 he’s keeping it down but all over the middle of the zone. In 2016 he’s using it as a perfect compliment to his slider and locating it superbly; down and in to righties and low and away to lefties.

Gomez was getting his sliders and changeups crushed in the zone to the tune of .438 wOBA vs. RBH and .313 wOBA vs. LHB, and by improving his command and keeping those pitches out of the zone, he’s dominating with them.

It’s the same plan, but executed way way better. And it’s showing up in his plate discipline stats. His Z-Swing (how often batters swing at his pitches in the strikezone) is down from 64.1 to 57.3 and his Zone% (how often he throws pitches in the strikezone) is down from 47.4 to 41.2. Not throwing strikes is how Gomez has posted a career-high 11.8 K-BB%.

With a 90 MPH sinker he’s not going to climb much higher in that closer K/9 leaderboard, but the improved command of his off-speed/breaking stuff and his confidence to throw it out of zone are a big reason why he is currently holding RHB to a .171 batting average against, and also happens to be leading the league in saves.