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We’re near the halfway point in the 2019 Reds season and there’s little question about the biggest pleasant surprise. That would be the pitching. Both kinds, starting and relieving.
Improvement in the starting rotation has been nothing short of miraculous. Over the previous three seasons, the Reds rotation sank to the dark bottom of major league baseball. By many measures they were dead last or close to it.
But after an offseason dedicated to #GetThePitching, we’ve witnessed a full resurrection. The reasons for improvement are many: (1) acquired better pitchers, (2) acquired fully modern pitching coaches, (3) provided better data for pitchers, and (4) better handling by the manager.
Behold these headline metrics:
- 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
(Data through Saturday, June 23)
The big, approximate picture: the Reds rotation has gone from 20% worse than league average to 15% better than league average in one season. This improvement has taken place in a run-scoring environment moving in the opposite direction. League ERA in 2018 was 4.15. So far in 2019, it is 4.46.
But it is real?
Have Reds starting pitchers just been lucky? Does the underlying data offer warning signs that the improvement is likely short-lived or is it durable? To answer those questions, we need to take a more detailed look into how the rotation has performed.
We’ll start with a few basic facts.
Age and Contract Status
The Reds have used only five starting pitchers with the exception of a spot start for Lucas Sims because of a double-header. Here is age and contract status data for the primary five:
Luis Castillo (26) and Tyler Mahle (24) are in their second year of team control, pitching for league minimum salary of $570.000. They could become free agents in 2024. Anthony DeSclafani (29) is in his second year of arbitration, earning $2.125 million. He could become a free agent in 2021.
Tanner Roark (32) is earning $10 million and can become a free agent next season. Sonny Gray (29) is pitching for $7.5 million this year. That contract 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
In plate appearance outcomes, pitchers have most influence over strikeouts and walks.
The K-BB% metric is interesting. All five Reds pitchers are better than average. Tyler Mahle rates the highest and Tanner Roark the lowest. The five are bunched relatively close together.
Composite Statistics
ERA is the most commonly cited composite statistic for pitchers, but it has severe limitations. Metrics like FIP, xFIP and SIERA have been developed to correct some of those weaknesses. They have been proven more accurate than past ERA to predict future pitching performance.
What they show: 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. Tyler Mahle has pitched better than commonly perceived. Sonny Gray’s stuff has been better than his outcomes, too.
Those are composites. Let’s break it into components using Statcast data.
Command and Dominance
Zone% is the percent of pitches thrown in the strike zone. Reds starters in general are a little low in this category, except for Tyler Mahle. Luis Castillo stands out as having an extremely poor Zone%. In fact, FanGraphs has a similar metric, and Castillo is last among MLB starters with at least 40 IP. Dead last out of 128 pitchers.
It’s good for pitchers to find themselves at the top of the First Pitch Strike% metric. The best fifteen include Clayton Kershaw, Madison Bumgarner, Kenta Maeda, Masahiro Tanaka, Chris Sale and Zack Greinke. A pleasant surprise: Tyler Mahle rates ninth best. Grey, Roark and DeSclafani under a bit under average. Luis Castillo is worst in the major leagues in this category, too.
Edge% indicates the percentage of pitches on the edge of the zone. It’s an indication of command. Reds pitchers are clumped around league average in Edge%. Tyler Mahle again is the best and Castillo the worst.
Chase% measures the number of pitches outside the strike zone the pitcher induces the batter to swing at. Luis Castillo is above league average in this. Anthony DeSclafani is tops on the Reds staff.
SwStr% (first column of the strikeouts and walks chart above) is a measure of dominance. It is the percent of pitches where the batter swings and misses. Luis Castillo is top ten in this category. The other pitchers are clumped around the middle.
Batted Ball Profile
Research shows that pitchers don’t have a huge amount of influence over the ball once it’s put into play. But they do have some, particularly GB%.
Castillo and Gray have been terrific ground ball pitchers. Mahle has been average. Roark and DeSclafani have been fly ball pitchers.
The other metrics speak to the ability to minimize power. EV-LD/FB is average exit velocity on line drives and fly balls. EV>95 is percent of balls allowed with an exit velocity of 95 mph or above. Barrel% are the percentage of barreled balls allowed (small sample size caveat in full force here).
Luis Castillo has been better than average. The other starters are about average on line drives and fly balls, below average on hard-hit and better than average on barrels. That’s a mixed bag of data. Again, it’s unclear if pitchers have much control over hard hit balls.
It could be that contact outcomes are the independent variable and the pitcher ratings the dependent variable, not the other way around as most people presume.
Quality of Contact
We can look at “expected” stats to measure the quality of contact the pitchers are giving up. The final two columns compare actual wOBA with luck-and-defense neutral outcomes.
Luis Castillo has been effective at minimizing quality contact. Sonny Gray has been outstanding, too, but not as good as Castillo. Tyler Mahle has been average. Tanner Roark and Anthony DeSclafani have been a little worse than average.
Castillo, Gray and Mahle have had actual outcomes close to what luck-and-defense neutral measures would predict. Anthony DeSclafani has been a little unlucky. Tanner Roark has been lucky.
Summary
Overall, Reds starters have been terrific collectively and also individually, for the most part.
Warning signs include: (1) Luis Castillo’s high walk-rate and low strike throwing, (2) Tanner Roark’s luck on home runs. But on the other hand, Tyler Mahle and Sonny Gray have been a little bit unlucky with outcomes relative to how they’ve pitched.
The sample size is still relatively small (15 or so starts) but when you look at it all together, the underlying data shows the substantial improvement in the Reds rotation is more likely durable than fluke.
