Remember #GetThePitching ???
We’re nearing the season’s halfway point. Let’s look at the state of the Reds starting rotation. First, we’ll see where it ranks as a whole compared to other National League rotations, then we’ll examine data for individual pitchers.
Before we tackle 2019, let us take up the horrific but necessary task of remembering the recent past. From 2016-2018, the Reds had the worst starting pitching in the NL. The team averaged 20% worse than league average in ERA and FIP. They were 10% below average in xFIP, strikeouts and ground ball percentage.
The litany of names provides another grim reminder: Alfredo Simon, Scott Feldman, John Lamb, Rookie Davis, Asher Wojciechowski, Lisalverto Bonilla, Bronson Arroyo’s Farewell Tour, Tim Adelman, Deck McGuire and on and on and no more.
Now the good news: In 2019, the Reds rotation has shown astonishing gains.
- Second in ERA, 19% better than NL average
- Third in FIP, 13% better than NL average
- Second in xFIP, 9% better than NL average
- Third in Strikeout-Rate (K%), 11% above NL average
- Sixth in Ground Balls (GB%), 4% better than average
Roughly speaking, the Reds have gone from 20% worse than league average to 15% better than league average in one season. Coming up with the causes will be left for another post. But they certainly include: (1) acquiring better pitchers, (2) better pitching coaching, (3) more information from the analytics department, and (4) better handling by the manager.
Every 2019 Reds game has been started by one of five pitchers, with the exception of a spot start for Lucas Sims because of a scheduled double-header. Let’s begin by looking at the age and contract status for the primary starters.
Luis Castillo (26) and Tyler Mahle (24) are in their second year of team control. They are pitching for league minimum salary of $570.000. Barring a negotiated deal, they will do the same next year, with their three years of arbitration starting in 2021. They could become free agents in 2024.
Anthony DeSclafani (29) is in his second year of arbitration, earning $2.125 million. Again, barring an extension or negotiated deal, his salary will be subject to arbitration again in 2020 and he could become a free agent in 2021.
Tanner Roark (32) is earning $10 million. He’s the second highest paid Reds player in 2019, following only Joey Votto. Roark can become a free agent next season.
Sonny Gray (29) is pitching for $7.5 million this year. That amount was negotiated by Gray and the Yankees and covered his third arbitration season. Gray and the Reds subsequently worked out a 3-year extension covering 2020-2022 for about $10.1 million a year. The Reds have a $12 million option for 2023.
Strikeouts and Walks
Next, let’s analyze the starting rotation’s strikeouts and walks, the two outcomes most under control of pitchers, along with the NL average. Statistics are through Saturday, June 22.
Luis Castillo induces the most swings and misses and has the highest strikeout rate, well above league average. Sonny Gray’s K% is 4.3% above average. The other three starters are also slightly above average.
Castillo’s walk rate is the highest of the five and well above league average. Tyler Mahle has the lowest BB%, less than half of Castillo’s rate. Gray’s rate is a little high. Roark and DeSclafani are right around average.
The K-BB% metric is interesting. All five Reds pitchers are better than average. Tyler Mahle rates the highest and Tanner Roark the lowest. All five are bunched relatively close together.
Batted Ball Profile
Next, let’s look at a few batting outcomes on balls in play.
There is a huge variance on ground ball percentage (GB%). Luis Castillo and Sonny Gray are far above average, both in the top five among NL starters. In contrast, Tanner Roark and Anthony DeSclafani perform well below league average. Tyler Mahle is right at average.
The chart includes two categories that measure power of contact – FanGraphs’ Hard-Hit% and Statcast’s percent of Exit Velocity above 95 mph. In both cases, the average is about 38%. The two metrics agree that Luis Castillo is well below 38%, so better than average. Sonny Gray, Tyler Mahle and Tanner Roark are right around average. Anthony DeSclafani is above average, but not a lot.
Weighted on-base average (wOBA) allowed factors in batting average, isolated power, walks and strikeouts. League average is .321. 85 National League pitchers have faced at least 100 batters.
Luis Castillo ranks #4. Sonny Gray has been the second-best Reds pitcher ranking #23. He’s followed by Roark #32, Mahle #42 and DeSclafani #57.
ERA and ERA-Projectors
BABIP (batting average on balls in play) is a function of defense, luck and quality of contact. League average BABIP is .294 and the vast majority of pitchers end up near that by the end of the season. That’s because they all face the same mix of batters over a sufficiently long amount of time. Odds are that pitchers far below or far above .294 can expect movement to the average.
FIP is a statistic that normalizes defense and luck. xFIP goes further and normalizes home run rate as a function of how many fly balls a pitcher gives up. SIERA is a more complicated statistic with more factors taken into account. All three stats have been shown to be better predictors of future pitcher performance than ERA, especially in relatively small sample sizes like 15 starts.
A good example for that is Luis Castillo. Prior to Saturday’s start in Milwaukee, his ERA was 2.26 but his FIP (3.54), xFIP (3.65) and SIERA (4.15) all pointed higher. The non-ERA stats reflected Castillo’s elevated walk-rate. As a result of Saturday, when Castillo walked five batters, three of whom scored, his ERA jumped from 2.26 to 2.56. At his current walk-rate, expect that ERA to continue to climb.
Sonny Gray also has a high walk-rate, though not as high as Castillo’s. Tyler Mahle’s performance looks much better with xFIP and SIERA than his ERA indicates. Tanner Roark looks worse. Anthony Desclafani’s ERA-estimators are about the same, but a little worse, than his ERA.
Overall, Reds starters have been terrific collectively and individually.
Even better, when you take it all together, there’s little in the underlying data to indicate the rotation’s fast start is unsustainable.
Luis Castillo can’t keep up his low ERA without fixing his walk-rate. Tanner Roark has been lucky with home runs per fly ball so far. On the other hand, Tyler Mahle has pitched better than commonly perceived. Sonny Gray’s stuff has been better than his outcomes, too.
Reds fans can be hopeful the rotation miracle won’t walk out the Reds clubhouse door anytime soon.