- Rating: 4.30
- Age: 27
- 2020 Stats: 19.2 IP, 21 H, 15 R, 13 ER, 4 HR, 9 BB, 16 SO, 5.95 ERA, 5.58 FIP, -0.2 bWAR
- 2020 Salary: league minimum
- 2021 Status: under team control, 2.011 years of service time
I was a bit surprised to see Lopez ranked above the last player I wrote about, Keury Mella, as it seemed to me that Yoan had an underwhelming season. While the usual small sample size warning applies, that ERA was more than two and a half runs higher than the one posted by Lopez in 2020 (3.45). However, it is worth noting that he was lucky to do so. His BABIP last year was all the way down at .233, the lowest on the team and ranking Lopez among the twenty lowest of the 341 pitchers with 60+ innings of work. His FIP was above five, pointing to a strong regression, and that’s exactly what happened. Those balls which become outs turned into hits this year (BABIP = .293), and Lopez’s numbers suffered as a result.
The team seemed to realize there was a bit of an issue, largely keeping him out of high-leverage situations: 18 of his 20 appearances were what Baseball-Reference.com calls low-leverage, more than anyone else on the D-backs. In some ways, Lopez was the team’s designated mop-up guy, in either direction. Half of his games saw Yoan come when the margin was already four or more runs (equally split between the D-backs being ahead and behind). Only a quarter fell into what Fangraphs call “shutdown” or “meltdown” outings, moving the Win Probability needle by more than 6%. He ended with two of the former, and three of the latter, while his overall Win Probability for the year was also negative, at -32%.
He remained the same kind of pitcher he was, basically throwing nothing but fastballs or sliders. This year, there were a few more of the latter, 45.5% of the time, compared to 39.4% in 2019. His fastball velocity was down a bit, from 96.3 to 95.5 mph, though that still made him among the hardest throwers on the team (Hector Rondon and Kevin Ginkel both averaged a tick more than Lopez). But Lopez did excel in one area: getting opposing hitters to chase pitches out of the zone. His swing percentage on those this year was 34.2%, best on the team among those with five or more innings. Indeed, batters swung at half of all Lopez’s offerings, compared to a team average of 44.3%.
That likely played into Lopez at least being efficient. He averaged only 3.29 pitcher per plate appearance, the lowest figure on the team (min 20 PA). Nothing illustrated this better than Yoan’s outing on September 19, where he recorded five outs on eight pitches. That was the quickest five-out appearance in franchise history, breaking a 15-year-old record of nine pitches, set by Mike Koplove. The downside of this contact is, there just weren’t very many outings this year where you could call Lopez dominant. Over eleven one-inning appearances, he only once had more than a single strikeout in a game, and his overall K-rare of 18.4% was again significantly below MLB average (22.7%).
It seems odd to think of a hard-throwing reliever as someone who pitches to contact, but that seems increasingly to be what Lopez looks like. Only Zac Gallen rolled up more double plays than Lopez for the D-backs, and he was also the only pitcher on the team to generate more ground-balls than fly-balls, his GB/FB spiking from 0.78 to 1.21. Was this a result of him locating his slider further down in the zone? Could be - below, you’ll find a heat map of the locations of the pitch, last year (on the left) and this (on the right), and you can see there definitely seems to be more pitches in that area. Though, generally, Lopez did seem to have more variation in his location, as shown by less red in 2020. Was this by design?
Despite being thrown less frequently that his fastball, the slider was responsible for 11 of his 16 strikeouts, all but one of those being swinging K’s. Here’s a video of five of them, which show how the pitch can be effective when he throws it down in the zone.
What of the future for Yoan? The struggles Lopez has gone through, on his way to the major-leagues, have been well-documented, and don’t need rehashing again here. However, he turns 28 next month, and they can no longer be used as an excuse. While his overall ERA is still good (3.93, an ERA+ of 115), the career FIP remains north of five (5.04), and if that’s what we can expect going forward, the team has better options. His walk-rate this season was above four per nine innings, and when you’re only striking out seven per nine, that’s not a recipe for success. His role in the 2021 bullpen is to be determined, but it would seem by no means guaranteed, especially if he can’t cut back on the free passes.