by 
We are notoriously impatient creatures; we want the ends without the messy means. That’s true of many things: luxuries, physiques, and baseball pitchers. But curveballs don’t bite based on natural talent alone, and fastballs zoom out quicker than they zoom in if a pitcher doesn’t learn to locate it. There’s a reason not many Mike Leake’s exist; it takes thousands of pitches and multiple seasons of growing pains and adjustments to succeed in the Major Leagues.
As fans, we hate to wait, often comparing unfinished young arms with the outliers who burst onto a MLB mound without many setbacks. How easily we forget the years it took before Johnny Cueto and to a lesser extent, Homer Bailey, became effective pitchers.
Before the 2017 season, Tyler Mahle was rated the 16th best Reds prospect by FanGraphs. On that list, Mahle sat behind Sal Romano, Rookie Davis, and Robert Stephenson, all guys that threw harder and had better breaking stuff. It was that season that Mahle’s velocity would tick up, and his elite command shined in the upper minors, earning him four starts with the Reds.
Since then, Mahle has had his ups and downs in the Major Leagues. He looked dominant at times in 2018 until he seemingly wore down and fell apart in July. In 2019, he has an unsightly ERA of 4.94, but looking at his season more holistically, he’s developing right on schedule.
ERA is valuable; however, it has a lot of noise in it. A pitcher with a good defense behind him has an advantage that others don’t enjoy. When a starter leaves a game with runners on base, he can be charged with runs allowed by the reliever.
Mahle has been the victim of the latter to the extreme: Tyler Mahle has left 10 runners on base when he’s been replaced during an inning this year. Nine out of ten have scored. That’s wildly unlucky. Usually, about 30% of these runners score. 90% of Mahle’s have scored. The Reds other starters have fared much better in this category:
- Roark 14-2
- Castillo 16-5
- Gray 15-4
- DeSclafani 14-3
- Bauer with Cleveland 19-4
- Bauer with Reds 4-2
If Mahle’s bullpen mates had been more effective this season, his ERA would be better than average. Even so, Mahle’s season has plenty to like that suggest he’s made significant strides.
First, Mahle’s elite command has shown through at the highest level. His BB% has dropped by almost 5%, down to 5.8%. That rates well above the league average for starters (7.7%). He just does not give out free passes and by doing so, he forces batters to make solid contact to beat him. Mahle has also managed to strike out more batters this year than he did last year, even though he’s missing bats at a slightly lower rate.
More strikeouts and fewer walks? Important steps forward for the 24-year-old.
Along with a better GB%, Mahle has improved his predictive stats quite a bit:
Mahle was below average by these metrics in 2018. This season, he has been above average, improving by a significant margin.
Other helpful metrics also reflect this improvement. xwOBA measures performance based on strikeout and walk rates as well as the quality of contact batters make against a pitcher. An average pitcher has an xwOBA between .315 and .320. Mahle did not rate well last season (.336), but he has been much better in 2019 (.310).
That improvement occurred not only because of better strikeout and walk rates, but because he has induced more ground balls and weaker contact than last season. Still, the batted ball data shows that when batters do make contact, they do damage against Mahle.
Mahle’s exit velocity and hard hit percentage, balls hit 95 MPH or more, are in the bottom 37% of the league. For the second straight year, he has a poor home run per fly ball rate. What does that mean?
Mahle’s xFIP and other advanced numbers may be a tad generous. Some pitchers have home run rates that don’t normalize and while Mahle may get better at this, we should consider that he might be a high home run guy.
Still, even with a worse HR/FB percentage this season, his numbers are significantly better, and he seems to be making progress with his secondary pitches. In almost the exact same number of innings, Mahle has struck out 50 batters on secondary pitches in 2019 compared to only 31 in 2018. The splitter and curveball he added this year have rated positively according to pitch info data. Both his slider and changeup rated poorly last season.
Mahle is developing well. He made adjustments to his secondary stuff and the command that got him to the big leagues has shown through. While Mahle’s xFIP may give him a little too much credit, he has pitched much better than his ERA. He should have the inside track to start in 2019, and if he keeps progressing, Mahle will lock up a rotation spot for years to come.
[Featured image: https://twitter.com/Reds/status/1137134044695547904]
Nice article Nick. Mahle is close. I d still like the Reds to get a good lefty starter with Mahle being depth.
Great article. I was at the game Friday and liked his effectiveness until he gave up some loud contact after the two soft ‘hits’. Seemed like a good learning experience on his way up the curve; more effective, but still not executing as fully and consistently as he will in the future.
Glad you mentioned his secondary offerings at the end – that has been my biggest question about his ultimate success. Can you elaborate a little on how effective the new splitter and curve are at this point?
Sure! We can good Pitch Info pitch values as a good summary. Fangraphs does a good job of explaining the stat:
“Essentially, there is an average run expectancy for each count (0-0, 0-1. 1-0, etc) and the change from from one to the other is the run value we use to create the pitch value. For example, if we start in a 0-0 count we begin at a perfectly average 0.0 run value (because all PA start as an average PA) and then the run expectancy of a 1-0 count is 0.04, meaning the value of taking that pitch for the hitter was +0.04 and -0.04 for the pitcher. If the next pitch is a strike, the run expectancy of a 1-1 count is about -0.02, so the batter gets -0.06 and the pitcher gets +0.06 from moving from the +0.04 world to the -0.02 world. Those run values are attached to the type of pitch thrown in each case, so if both were fastballs, the total wFB would be -0.02 for this at bat so far. Or -1.00 wFB/C, when scaling to 100 fastballs.”
Mahle’s split and curve rate like this:
Split: 3.3
Curve: 1.2
Last year, his slider (-4.2) and changeup (-10!) both rated poorly, so this is a significant step forward. Neither the splitter or curve are dominant. For example, Amir Garrett’s slider has an 11.6 on this scale. Luis Castillo’s changeup is over 27. Those are extreme examples because those two pitches are some of the best in the game, but they provide some context.
Essentially, his splitter has been an above average pitch and the curve has been close to average. Neither is dominant.
A few other numbers of note: Mahle uses the curve 23% and the splitter 12% of the time. Here are their batting avg, slugging percentage and ISO against:
Split: .250/.350/.100
Curve: .212/.424/.212
Batters have more hits off the splitter, but they are doing more damage against the curve. This season, the splitter has produce groundballs at over a 60% clip when it’s put in play. It’s xwOBA is the lowest (.237) among Mahle’s pitches this season. The curve gets put in the air more often and has a respectable .304 xwOBA.
Awesome, thanks! That’s the first time I’ve delved into the Pitch Values – enlightening info. Great to see that a new pitch (the splitter) is getting such positive results.