Part 1 – The Problems with ERA | Part 2 – Isolating Pitching| Part 3 – Pitcher Arsenals

In the first three entries of this series, Steve Mancuso showed us how to effectively evaluate a pitcher using a plethora of different stats and technologies. Today, I’ll be using these methods of evaluation as a filter to take a look at the 2019 Reds pitching staff.

At Redleg Nation we aren’t shy to use “advanced” statistics. I don’t think I’d be doing a disservice to any of the amazing writers here if I said we all wish these statistics were made more readily available to the average Reds fan, whether through radio and television broadcasts or being featured more prominently on the scoreboard at the ballpark. We use these statistics because A) They aren’t that much more complicated than ERA (an average baseball fan can calculate ERA just as easily as they can xFIP), B) They can tell a better, more complete story of a pitcher’s ability and level of success (see the rest of the entries in this series), and C) As a somewhat large source of opinion and analysis in Redsland, this is one of the only places the average fan might stumble across these numbers.

So let’s take a look at how the Reds starting rotation fares when using these tools to evaluate. We’ll also compare them to the top performer in each category, as well as to Dallas Keuchel, a favorite free agent target for many Reds fans. All of the tables below refer to 2018 statistics, and if available, sorted by Starting Pitchers only.



If you’re uncomfortable using advanced statistics to evaluate pitching, that’s fine too! Many of our readers grew up reading ERA on the back of baseball cards. The point of keeping statistics in the first place is so that fans can keep track of how their team and their favorite players are faring over the course of a season, a decade, a career. You can do that with ERA to a certain extent, and can get a pretty good idea of performance. For many fans, this is enough.

Predictably, the Reds don’t show up well on the ERA table. And since ERA is still the primary way the majority of fans evaluate pitching, it’s easy to see why the Reds are still seen as bottom dwellers by many. Hopefully the rest of this article will show you that this sentiment is questionable at best.

Also, note Dallas Keuchel’s ERA here. He’s commonly labeled a #1 starter by many fans who would like very much for the Reds to sign him. If we look at ERA alone, he’d certainly be in the conversation as one of the best options for the Reds starting rotation. We’ll continue to keep tabs on him as we run down the list.



From earlier in the series:

Fielding Independent Pitching measures how the pitcher actually pitched. The pitcher gave up those home runs and walks. He struck out those batters.”

“Let’s say we wanted a version of FIP that “normalizes” home runs hit across luck and stadium dimensions. The way to do that would be to remove HR from the equation and replace it with a variable representing a pitcher’s FB% in relation to the league FB%. That statistic is called xFIP.”

“It is possible to adjust certain statistics for park effects. The convention among baseball statisticians is to put a minus-sign at the end and scale the statistics to 100. You can find ERA-, FIP- and xFIP-. Every point below 100 is a percentage that a pitcher is better than average. For example, a pitcher with an FIP- of 90 is 10 percent better than average, taking into account ballpark.”

That’s more like it! As we pointed out earlier in the season, FIP and xFIP do a much better job of accurately evaluating pitcher performance. The whole point of these statistics is to see how pitchers actually pitched, stripping away other factors.

We see the Reds who were on the team in 2018 show up really well specifically in the xFIP leaderboard. This makes sense because xFIP normalizes HR/FB rate, and because Great American Ballpark turns fly balls into home runs more than just about every other major league park, Castillo and DeSclafani get some credit back to their names here.

Keuchel continues to look decent here, but maybe not the frontline starter many Reds fans claim he might be upon signing.



“SIERA assumes the pitcher has average luck, defense, sequencing, park factors and home runs. It incorporates strikeouts, walks, HBP and FB% as things under the pitcher’s control. What SIERA adds to xFIP is an attempt to model the small fraction of batted balls that the pitcher can influence. Studies show that SIERA is a better predictor of future pitching than xFIP, FIP and ERA.”

If we believe that SIERA is one of the best ways to predict future pitching, the Reds certainly look to be in good shape for 2019. If we agree that there are 30 #1 pitchers, 30 #2 pitchers, 30 #3 pitchers and so on, the SIERA leaderboard suggests the Reds have three #2 pitchers and two #3 pitchers making up their rotation. That’s not bad at all.

A few things are becoming more clear as we work down this list: Luis Castillo was great last year, except for when he wasn’t. Without those bad few outings, Castillo would easily rank near the top of all of these lists. With him being so young, that’s a good thing.

Alex Wood isn’t far behind him, either. Wood is consistently the top one or two Reds pitcher on all of these lists, suggesting he might be the best pitcher on the staff. That’s interesting for a guy not many believe will pitch Opening Day.

Lastly, Anthony DeSclafani might be back. The ERA wasn’t great, but all of Disco’s fielding independent stats scream #2/#3 starter. If the Reds can get that kind of production out of their #5 guy, it’ll be a good season for pitching.



“Velocity is highly correlated with strikeout rates…Strikeouts are a huge factor in pitcher success. Strikeouts prevent the ball from going into play. It’s the one outcome where hitters won’t get on base and runners don’t advance. Fly balls and ground balls can produce hits. Small increases in pitch velocity can make a big difference in a pitcher’s success. It’s a great way to evaluate pitchers.”

For those of you wondering, Noah Syndergaard had the fastest average 4-seamer (97.6), Sinker (97.3) and Slider (92.0) of qualified pitchers (minimum 1,500 pitches thrown). Dylan Covey had the fastest Cutter (93.0), Tyler Glasnow had the fastest Changeup (91.7) and Lance McCullers Jr. had the fastest Curveball (85.9).

I’ve color coded these cells for easy reading. Immediately a few things pop out. The difference in speed from Luis Castillo’s hard stuff (4-seam, Sinker) and soft stuff (Slider, Changeup) is pretty huge. It has to be hard for hitters to sit on any of his pitches with that sort of disparity. Anthony Desclafani throws a lot harder in comparison to the rest of the league than I would have thought. And Alex wood should be interesting to watch – he’s got slow fast stuff, and fast slow stuff.



“(Aaron) Sauceda finds that ACES (Arsenal Combination Estimate Scores) produces a tight evaluation of pitchers. The correlation of an ACES score from one year to the next is 76% or seven times higher than that for ERA. The ACES score doesn’t include any batted ball outcome or run production, just actual pitch characteristics, and it better predicts ERA than ERA itself.”

ACES basically tries to evaluate the actual “stuff” a pitcher has. While we don’t have access to the ACES scores (it was developed by Fantasy Baseball people, and a subscription to SportsLine is needed to gain access to the leaderboards), the creator of ACES Aaron Sauceda released the top 10% of ACES scores when he first announced the score back in February. According to ACES, Luis Castillo has the 9th best “stuff” in baseball, ahead of guys like Jacob DeGrom and Blake Snell, and just behind Chris Sale, Charlie Morton and Zach Wheeler. Those of us who watch Castillo pitch every 5th day aren’t shocked by this, but it’s nice to see the fantasy guys getting it right.


So, how does this evaluation make you feel about Reds pitching heading into 2019? What stats do you use to evaluate pitching for yourself? Has this series made you rethink the way you’ll evaluate pitching going forward? Still think the Reds should sign Dallas Keuchel? Let us know in the comments!

10 Responses

  1. lost11found

    Thanks to Jordan and Steve for putting this series together.

    Regarding this quote about SIERA, “Studies show that SIERA is a better predictor of future pitching than xFIP, FIP and ERA.” How much better is ‘better’? How far does its predictive value drift from the actuals? And how does that compare with other pitching metrics?

  2. SultanofSwaff

    Wow. This has me feeling pretty good about their chances. Of course, I’m super curious as to how our division rivals rate……but too lazy to do the research. lol

  3. Sliotar

    Keuchel was more than just “a favorite free agent target for many Reds fans.”

    It was reported widely that the Reds were pursuing him, and later, it was published that… “According to Paul Daugherty of the Cincinnati Enquirer, the Reds are out on Dallas Keuchel because they didn’t like what they saw on his medical reports.”

    The reality is that the Reds did not “get the pitching” via free agency and cannot realistically replicate what they did this winter over 2-3 more seasons…it would use up the farm system. The team isn’t in the Brewers “win now at all costs” spot (yet).

    For this season, the rotation as is projects to be adequate, if shielded properly (no 3rd time through lineup/watching pitch counts). The bullpen is crucial and the biggest unknown component of the club, IMO.

    • Old-school

      Agree on bullpen concerns.
      DW has talked about flexibility and with expiring contracts this year, options are many for SP. A deep FA starting pitcher class next off-season is one option. Mahle and Santillan are viable internal options.

  4. VaRedsFan

    Nice article. A few things…

    1. “We see the Reds who were on the team in 2018 show up really well specifically in the xFIP leaderboard. This makes sense because xFIP normalizes HR/FB rate, and because Great American Ballpark turns fly balls into home runs more than just about every other major league park, Castillo and DeSclafani get some credit back to their names here.”

    Would it be fare to say, since guys that pitch for the Reds are graded on a curve for pitching in one of the worst parks, therefore they don’t benefit from having a better xFIP, because they are still stuck pitching in GABP. Also, won’t the three guys the Reds acquired, will have worse numbers this year because of the same ballpark factor?

    I’ll try to answer my own question….Is it safe to assume that if Pitcher X, from another team, and has the same xFIP as Castillo, comes to GABP and pitches, that it would be an equal pitching matchup on paper?

  5. WVRedlegs

    Great series by both writers. Nothing wrong in broadening one’s knowledge base.
    That was pretty cool to place Keuchel and Sale/de Grom in the tables for a nice little barometer and comparisons.
    This makes me excited to see this rotation in real games. Alex Wood at the top of 2 of the 4 tables within the Reds staff. And he is 2nd to only Castillo in the other 2 tables. This is a big opportunity for Wood. Looking forward to his 2019. If Gray takes to Johnson’s tutelage like I believe he will, that is shaping up for a pretty good top 3 in the starting rotation, Wood-Castillo-Gray. Roark will be no slouch in the #4 spot. A lot riding on a healthy Desclafani. A healthy staff from 1 through 12 or 13.
    Great series. Thank you.

  6. Warren Leeman

    This not only makes me even more excited for the beginning of the season, but the starting pitching options available for the 2020 season. Castillo, DeSclafani & Gray are controlled thru the 2020 season. The Reds have a chance to negotiate with Wood thru the 2019 season in an effort to extend his contract. Sale and Cole are obvious #1’s as FA for 2020, but they will be hotly pursued by the big pocket teams. Wheeler would be a nice #2 to add as a FA in 2020, with or without Wood extended or signed as a FA. I think the Reds need to let Roark test the FA market unless he can be signed to a very reasonable (AAV & length) contract. Hopefully only 1 starting pitcher would need to be replaced for the 2020 season with an in-house prospect.

    SIERA (RANK) – Pitcher
    2.27 (01) – Chris Sale, age 31
    2.91 (06) Gerrit Cole, age 28
    3.85 (43) Luis Castillo, age 25
    3.87 (46) Zack Wheeler, age 29
    3.92 (48) Alex Wood, age 28
    3.96 (52) Anthony DeSclafani, age 29
    4.05 (59) Trevor Cahill, age 31
    4.25 (68) Kyle Gibson, age 31
    4.37 (80) Sonny Gray, age 29
    4.38 (82) Tanner Roark, age 32

  7. Warren Leeman

    The year-to-year correlation for ACES of 76% is impressive. The article seems to imply that the year-to-year correlation for ERA is 10%-11%. Any data available for the year-to-year correlation of ERA, FIP, xFIP & SIERRA?

    • Aaron Sauceda

      Hey Warren — Aaron here of CBS, creator of ACES. Appreciate your guys excitement around the metric!

      You are right that ERA is a really volatile stat year-to-year. ERA estimators like FIP, xFIP and SIERA are much stickier, with an r-squared between itself in year one and year two of approximately 0.31, 0.44 and 0.45 (i.e., xFIP and SIERA are stickier than FIP).

      They also project future ERA almost 2x better than ERA itself — roughly a 0.16-0.18 r-squared between year one FIP/xFIP/SIERA and year two ERA. To your point, year one ERA to year two ERA is ~0.11 — ERA estimators still leave a lot to be desired, but certainly better than using ERA.

      Also, here were the Reds pitchers by ACES last season:

      Luis Castillo 96%
      Tyler Mahle 89%
      Anthony DeSclafani 83%
      Cody Reed 71%
      Sonny Gray 69%
      Sal Romano 65%
      Alex Wood 33%
      Brandon Finnegan 18%

      Keep in mind velocity-driven measures like ACES tend to not be crazy about LHP like Wood/Finnegan since LHP throw slower on average. Still,certainly plenty of intrigue there!

      Anyway, always happy to discuss baseball — feel free to find me on Twitter (@RotoPope). Best of luck this season!

  8. sixpack2

    I think our staff is great looking back on where we were. Let’s give the kids another year in AAA and see how the three Veterans, we have under contract, do this year. If they hold up, we add a top #1 and let one of the kid(s) graduate.