26 January 2015

Chris Tillman: Good Pitcher, Not an Ace

Since Chris Tillman became a permanent member of the Baltimore Orioles rotation in July 2012, one could argue that he’s been the team’s best starting pitcher, albeit on a pitching staff that has been less than stellar during that time.   Since the 2012 season, Tillman has pitched about 500 innings, with an ERA of 3.42, which is better than any other Orioles starter by almost a half of a run.  A difference of a half run of ERA isn’t trivial over the course of the entire season.  Assuming 200 innings pitched, it adds up to 11 or 12 additional runs prevented.
Chris Tillman (photo via Keith Allison)

The topic of whether Chris Tillman is an ace isn’t a new one.  It’s been covered elsewhere, and has been covered here at Camden Depot as well.  Our own Jon Shepherd took on the topic in 2013 after receiving a reader email and then again towards the end of the 2014 season in a post he wrote for MASN.  In his previous posts, Jon first attempts to define an “ace”.  While he used slightly different methods, in both instances he arrived at the same place: in any given year the league has roughly 10 “aces”.  He then follows that discussion explaining why he believes that Chris Tillman does not qualify as an ace based on his previously defined designation.

While I in no way disagree with the conclusion of the two aforementioned articles, both of them generally used Fangraph’s version of WAR (and the components that contribute to it) as the basis for measuring whether Tillman should be considered an ace.  However, fWAR, FIP, and the statistics that reward them have never been Tillman’s strong suit.  He isn’t especially great at striking batters out (of qualified starting pitchers, he ranks 47th in K% since 2012), limiting walks (ranked 82nd in BB%), and doesn’t do a great job of keeping the ball in the yard (ranked 105th in HR/9).  It’s no wonder that despite that 3.42 ERA mentioned earlier, Tillman has only been worth 5.6 fWAR since 2012, more than a win less than Wei-Yin Chen in only slightly less innings.

However, what Tillman has done well since 2012 is prevent runs, as noted by his 3.42 ERA during that time.  Run prevention plays a much bigger role in calculating Baseball-Reference’s version of WAR, so it’s not a surprise he’s been worth almost 3 more wins by their standards compared to Fangraphs over the same period of time.  It’s believed that certain pitchers have a skill that FIP is unable to capture, and will therefore post ERA’s that exceed their FIP on a regular basis (Matt Cain of the San Francisco Giants is the most recent example).  Since 2012, Tillman’s ERA has been better than his FIP by AT LEAST 0.67 runs each year (with a maximum difference of 1.32 runs during 2012).  Could Tillman be one of those rare pitchers that FIP just doesn’t understand?  It’s certainly possible, but it’s also probably too soon to tell (one could say the same for Miguel Gonzalez).

Hypothetically, let’s assume that Tillman does have the ability to regularly outperform his FIP.  If so, can he be considered an ace based solely on his ability to prevent runs?  In order to determine this, I looked at ERA+, which takes into account ballpark effects and the offensive environment of the era.  As Jon mentions in his articles, people can have many different views as to what constitutes an ace.  Because of that, I looked at the average, maximum, and minimum ERA+ values for the 10th, 20th, and 30th best pitchers from 1961 to 2014.  

I then compared those values to Tillman’s ERA+ numbers since 2012 to see where Tillman fits in, if at all.

*From 2012, when Tillman only pitched 86 innings
It’s only two plus years of data for Tillman, but if you squint and use the most broad definition of what is considered to be an ace (one of the top 30 pitchers in baseball), one could make an argument that Chris Tillman is an ace when considering run prevention only (he’s obviously doesn’t fit in the more stringent ace categories).  However, I personally don’t consider a top 30 pitcher to be an ace (I’m in the “10-15 aces” camp), and even though Tillman could be viewed as a top 30 pitcher in baseball in terms of run prevention, the fact that he isn’t close to being a top 30 pitcher in terms of FIP and fWAR (as detailed in the previously linked to posts) further diminishes what little case Chris Tillman already has as an “ace”.

Just because Chris Tillman isn’t technically a traditional ace, does not mean he isn’t a good pitcher.  If you prefer FIP, he’s likely a number 3 or 4 pitcher on a good team.  If you’re more partial to strictly run prevention, he could probably be considered more of a number 2 or 3 pitcher.  Either way, he should provide decent value to the Orioles, even as he enters his arbitration years (Tillman and the Orioles avoided his first arbitration hearing last week by agreeing to a $4.315 million contract).  Of course, how much value Tillman provides will depend on whether he is in fact one of those rare pitchers who can consistently outperform his FIP, and remain on the fringes of being a “run prevention ace”.


Jon Shepherd said...

Good article.

Just to clarify, because I love to over clarify things. I would argue that there are roughly 30 ace quality performances each year, but only about 10 aces per year. What I mean by that is that there are about 10 guys per year that you can almost be certain they will deliver elite performance. There are then about 20 guys who float in and out of elite performances. Those floaters may have one season, two seasons, perhaps even three seasons of non-consecutive elite performances, but I would not call them aces because it is difficult to expect them to perform at an elite level.

Anyway, hope that provides some clarity for anyone who did not feel the urge to click through to my original articles.

Matt Kremnitzer said...

That was an elite-level comment, Jon.

Anonymous said...

I believe you are tinkering with the age-old definition of an ace. The ace is to the best starting pitcher on the team. Chris Tillman is the ace of the Baltimore Orioles.

Nate Delong said...

Anon - An ace can have different definitions to different people. If that's that definition you want to use that's fine, but that's not the definition that I subscribe to. I would agree that Tillman could possibly be called the "ace of THE ORIOLES" (him or Chen), but I wouldn't call either an "ACE".

I probably didn't explain it well enough, but the reason I looked at the 30th best ERA+ over the years was to simulate an "ace for each team" scenario (I realize it's not accurate). Tillman barely made that cut.

Jon Shepherd said...

The definition I used, which I think I spelled out in those articles, is what scouts and other talent evaluators use. I am not using the sportswriter definition.

Jeff Stower said...

wow I say he is an Ace in the American league East in a hitters ball park to have a 3.34 ERA. He is just not a sexy over powering pitcher. Stop over thinking it. Is he top 10 ace no but he is a top 30 pitcher meaning he is an ace a #1 starter.

Philip said...

Regardless of how one defines Tilmans production(and I think the definition of his production is completely meaningless. Whether he is an "Ace"or not, he is undoubtedly successful, and we can expect that success to continue)we can all be happy that he is producing it as an Oriole, and not as a Mariner.

Jon Shepherd said...

Not sure if I am overthinking it, just using the scouts approximation and then, in those linked articles, I explained in a more accessible way because most people do not understand scouting and front office perspectives. However, one can define ace any way they wish.

Jon Shepherd said...

Also why should there always be 30 aces exactly? Talent distribution within a population is not a constant. There is not always a Babe Ruth around every year.

John Morgan said...

Good point on the "floaters." After all, Ubaldo Jimenez was performing at ace level not so long ago, if only for a limited time. Yikes.

One comment in Tillman's defense also: he has been very consistent. He may not be an "ace" but he is a very solid guy who gives predictable performance. That allows a team to plan around him to maximize what he provides, a trait that Showalter obviously values and uses to high effect. I doubt whether the analysis can capture it, but consistency is worth more than the raw FIP numbers show.

Michael Wallace said...

I think I agree most with Jon's idea of 10 consistent "aces" and around 20 other guys who float in and out of that distinction. I don't see Tillman as being an ace, but I think he's a solid 2/3 on a great team. I also think pitching can develop into a big strength for the O's in the upcoming seasons with Gausman and Bundy emerging. It was fun to think about Gausman, Bundy, Harvey, and Hoffman for that little while too lol.

Eric said...

Good article Nate. I do prescribe to your thinking as well, in that I do not believe Tillman is an ace. But I also agree with anon, however I'd word it differently. I would call him the "Leader of the Orioles Staff". In actuality he does not match the level of a top pitcher in the league so he is not an ace, but he is the best option (depending on your ideas, but Id rather him over Chen most days) on the team.

In all likelihood if I had to further clarify, Id put him in the 3rd tier of pitchers. Not ace, not definite number 1 starter, but rather a tweener 1/2 (leader of a team category) depending on the team.