A Quick Note About Brandon Maurer
Marc talked about this in the game thread last night, and lots of other people have noticed this before, so I’m not breaking any news here, but Brandon Maurer has a pretty serious flaw, and it was on full display last night; he’s got nothing to throw left-handed batters.
Maurer has four pitches, but he’s primarily a fastball/slider guy. He throws his slider a lot, in fact. Among qualified starters, PITCHF/x only has three pitchers throwing more pitches classified as sliders than Brandon Maurer this year. As you probably know, the slider has the biggest platoon split of any pitch in baseball. There’s a reason every situational reliever in baseball throws a million sliders. It’s why the Mariners have a bullpen full of match-up guys who just come in and throw slider after slider.
The slider is not a good pitch to opposite handed hitters, but it’s great against same-handed hitters. Pitchers who throw a lot of sliders tend to have huge platoon splits. Brandon Maurer has huge platoon splits.
Vs RHB: 17 2/3 IP, 16 H, 1 HR, 2 BB, 16 K, .250/.304/.359
Vs LHB: 12 IP, 19 H, 4 HR, 6 BB, 2 K, .359/.424/.717
A lot has been made about how bad Maurer was early, then how he “found it” for three starts, then “lost it” again last night. In reality, what actually happened is that he faced two teams with a decent number of LHBs in his first two starts, then had three starts against the RHB-heavy Rangers and Angels, then had to face a bunch of lefties again last night. His up-and-down performances have basically been tied to how many left-handers the opponent has been able to stack against him.
In general, right-handed starters are going to face more left-handed hitters than right-handed hitters, since most teams have enough hitters from boths sides to play the match-ups and get the platoon advantage against pitchers with big splits. For a pitcher to succeed in the rotation, he essentially has to be able to keep opposite handed hitters at bay, at least to a reasonable degree. The way most pitchers do that is with a change-up, which has a reverse platoon split.
Brandon Maurer has a change-up. When facing lefties this year, he’s thrown it 43 times. It has produced terrible results. Opposing batters have swung and missed at his change-up just twice, and they have a higher contact rate against his change-up (93.8%) than they do against his fastball (89.2%). Maurer knows his change-up isn’t a very good out pitch right now, which is why when he gets to two strikes against left-handers, he’s actually throwing 55% sliders and only 3% change-ups. When he wants a swing-and-miss, even against a lefty, he goes to a pitch that dives right into LHBs hot zones.
The difference between his slider against RHBs and LHBs tells the story. Per BrooksBaseball, Maurer has gotten 20% called strikes and 22% swinging strikes on his slider against right-handers. Against lefties, he still gets 19% called strikes, but the swinging strike rate drops to 10%. At-bats by RHBs that end with a slider result in a .194 average and .278 slugging percentage. At-bats against lefties that end with a slider result in a .438 average and .750 slugging percentage.
Brandon Maurer’s slider is a real weapon against RHBs, but he can’t keep featuring it against lefties like he is now. It is not an out pitch against opposite handed hitters. Pitches that move horizontally towards a hitter generally do very poorly. The change-up, curveball, and splitter do well against opposite handed hitters because they move up and down, not side to side.
Maurer has a curve ball, but he doesn’t throw it very much, and his change-up isn’t very good right now. He’s young, so it’s certainly possible that these pitches will develop and give him weapons against LHBs in time, but right now, he’s basically a righty specialist being asked to start. When he runs into RHB heavy line-ups, he’ll look great, because his FB/SL combination is very good against RHBs. When he runs into LHB heavy line-ups, well, you’ve seen what happens.
I like Brandon Maurer, and I think there’s potential for him to turn into a good starter at some point. But, right now, Brandon Maurer is at least one pitch shy of being a good big league starter. Either the change-up or the curve need to take a big step forward, or else he’s going to keep getting pounded by line-ups that have good left-handed hitters. There are a lot of good left-handed hitters in baseball. Asking Brandon Maurer to get them out right now is simply not fair to him, nor is it helping his development.
In the minors, Maurer could simply be told to throw x number of change-ups and curveballs each game in order to further develop those pitches. In the majors, his job is to get hitters out, and so he leans on the pitches he trusts the most. The problem is that he’s not really pitching that well, and featuring his fastball and slider on a regular basis won’t help his change-up or curveball get any better.
Unfortunately, the Mariners don’t really have any pitching depth. Aaron Harang would probably be on the chopping block if the team had any decent Major League starters in Triple-A, and they’d need two MLB starters in order to dump Harang and get Maurer more time in the minors. It is not clear where the Mariners can find another decent big league starter — Erasmo Ramirez doesn’t sound like he’s anywhere close to returning, and given the quiet nature of the team’s updates around him, I suspect we might not see him at all this year — much less two. So, Brandon Maurer is probably going to stay in the rotation, and he’s probably going to keep having these up-and-down performances based on how many LHBs the opposing manager can stick in the line-up against him.
Hopefully, his change-up and curveball can improve at this level, even without getting a lot of in-game practice. He needs more than just his slider.