The Mets have gotten fantastic production from their rookie pitchers this year and the tendency is to lump them in together, especially Robert Gsellman and Seth Lugo. It seems to me that Lugo has received more publicity, so the focus today will be on Gsellman. The man with the funny name and the facial look of a hungover Jesus has been tremendous so far for the Mets. And he just might be able to keep it up.
In his age 22 season, Gsellman has advanced from Double-A to the majors, not bad for a guy who was ranked 18th in our top 50 prospect series. And it wasn’t like we blew it with the ranking. Most of the feedback on the article, which featured three other players, was about Patrick Mazeika. The one commenter who mentioned Gsellman didn’t feel his stuff was sustainable. MetsMinors assembled a list from 12 different sources and Gsellman ranked 11th overall and was even left off one list completely.
So, did the prospect guys miss him or is the Mets’ system better than we thought?
In the MetsMinors list, and ours, he was behind Milton Ramos, so we can’t give the prospect guys a pass. But as mentioned by DED yesterday we may have become too dismissive of pitching prospects who are not in the class of the guys who started for the club in the playoffs in 2015. Not everyone throws 100 mph and not everyone comes with a four-pitch repertoire of killer stuff. Doesn’t mean they can’t succeed in the majors.
So, how is Gsellman succeeding here in the early going of his MLB career? Among other things, he’s not giving up a ton of hard contact, he’s keeping the ball primarily on the ground – and in the park – and he’s having good fortune with his strand rate. Those things are making up for too many baserunners and a less than impressive strikeout rate. It all adds up to a 3.08 ERA after 26.1 IP.
Gsellman’s 3.29 FIP is right in line with his ERA. The big issue is that his xFIP shows a different story, with a 4.13 mark. Gsellman has allowed just 1 HR with the Mets so far and has a 4.8 HR/FB ratio. The team’s pitching staff has a 10.4 mark and the MLB average this year is a 12.9 rate. Since xFIP normalizes HR rate, it’s easy to see why that’s so different from both his actual ERA and his FIP.
So, the question becomes if Gsellman can continue to keep the ball in the park to the rate at which he has done so already. And there may be hope that the answer is a partial yes. The first thing to understand is that no qualified pitcher on the FanGraphs leaderboard has a HR/FB rate as low as Gsellman’s 4.8 mark. The best rate is the 7.1 mark of knuckleball pitcher Steven Wright. The best for a traditional pitcher is Tanner Roark’s 8.7 mark. In fact, only nine of 78 pitchers have a HR/FB rate in single digits.
However, there is some reason for optimism. Throughout his career, with the notable exception of Las Vegas, Gsellman has done a strong job of limiting the HR ball. We’re going to switch from the more exact HR/FB rate to HR/9, simply because that’s easier to find with it being right on the FG player page, while minor league HR/FB rate is not. Gsellman has a 0.34 HR/9 rate in the majors. In Double-A this year he had a 0.27 rate. Last year he had a 0.39 rate in Double-A and a 0.19 mark in Hi-A. Outside of Las Vegas, his highest HR/9 rate for a stop with more than 15 innings is the 0.62 mark he put up in Kingsport in 2012.
And then there was Las Vegas. In those hitter-friendly environments of Vegas and the PCL, Gsellman posted a 1.48 HR/9. Some pitchers are better able to handle those conditions than others. For example, Noah Syndergaard had a 0.61 HR/9 mark in 2015 and a 0.74 mark in 2014. But old pal Jack Leathersich allowed 7 HR in 50.2 IP for a 1.61 mark.
For whatever reason, Gsellman became homer-happy in Vegas. We all know this sort of thing happens. The question is if it defines the player. I think it’s reasonable to assume that Gsellman is not a true-talent 1.48 HR/9 pitcher. But is he closer to that or the 0.34 rate he has in the majors? For his sake, he best hope for the latter.
And while he’s extremely likely to give up more homers going forward, Gsellman has done a fine job of limiting the number of fly balls that opposing batters generate against him. His FB% checks in at 28.4 and while that’s a really low mark, that would only be the 15th-best mark in the majors among qualified pitchers, instead of the best mark by far like with his HR/FB mark. And fly ball rate for a pitcher stabilizes quite early, needing just 70 balls in play for that to happen. Gsellman exceeded that mark in his last start.
Because of his minor league history, there’s hope that Gsellman can run a HR/FB rate lower than league average, even if much closer to that than his current rate. And with his low FB%, Gsellman should give up fewer HR than a normal pitcher, even with a completely normal HR rate.
Of course, it’s more than HR rate. Hansel Robles has an 8.5 HR/FB rate, considerably lower than league average. Where Robles gets in trouble is that when batters make contact, they hit the ball really hard, even if not over the fence. Robles has a 37.2 Hard%, compared to a league average mark of 31.5%. Meanwhile, Gsellman has a 29.1 Hard%. Among the Mets, Jeurys Familia has by far the best Hard%, with a 21.4 mark. And Erik Goeddel has by far the worst, with a 49.4 mark.
So, we’re encouraged by Gsellman’s FB% and his low rate of allowing hard contact. We can be optimistic that he can maintain a lower than average HR/FB rate, even if not to the extent he has to date. So, it may come down to two things with the rookie. Can he lower his walk rate (and WHIP) and can he continue to strand so many runners? Currently, he has a 3.42 BB/9 and a 1.41 WHIP. For a guy who doesn’t strike out a ton of batters, he has to do better here if he wants to succeed. In parts of two seasons in Double-A, Gsellman had a 2.4 BB/9 and a 1.18 WHIP. Obviously, we would expect these numbers to go up against MLB hitters. But hopefully he can move a little towards those numbers in the rest of his time with the Mets.
And as you probably already know, Gsellman has a 79.2 LOB%, compared to a 72.9 league average. He’ll have more control over his walks and his HR rate, which will go a long way towards determining his success in the majors. But none of us will complain if he has some good fortune with his strand rate to go along with those other things.