Today’s email from Marc S.:
My friends and I are arguing over whether Chris Tillman is an Ace?
To me an Ace needs to be one of the top 15-20 pitchers in the Game. Its not simply the #1 starter but clearly a top line pitcher in most teams.
Over the last calendar year Chris Tillman is 18-4. (Since July 1) through today June 29th. He has not lost more than once in any of those months (July, Aug, Sept, April, May and June) His ERA over that 18-4 stretch is under 3.5. To me that sounds like an Ace.
What is an ace?
This is a definition that varies wildly and is often, in my opinion, used excessively. I think some of that excessive use is due to optimism in scouting reports where players are mentioned as having ace potential. That use gives the impression that baseball is abound with aces where I contend that it truly is not. As an example, I’d like to offer the following tables which shows the top 30 fWAR starting pitchers in 2010, 2011, and 2012.
|Cliff Lee||Roy Halladay||Justin Verlander|
|Ubaldo Jimenez||Justin Verlander||Felix Hernandez|
|Justin Verlander||Clayton Kershaw||Clayton Kershaw|
|Josh Johnson||CC Sabathia||Gio Gonzalez|
|Roy Halladay||Cliff Lee||Yu Darvish|
|Francisco Liriano||Dan Haren||Cliff Lee|
|Jered Weaver||Jered Weaver||Chris Sale|
|Adam Wainwright||C.J. Wilson||David Price|
|Felix Hernandez||Doug Fister||Zack Greinke|
|Jon Lester||Ian Kennedy||CC Sabathia|
|CC Sabathia||Daniel Hudson||Johnny Cueto|
|Colby Lewis||Matt Garza||R.A. Dickey|
|Zack Greinke||Matt Cain||Wade Miley|
|Clayton Kershaw||Felix Hernandez||Max Scherzer|
|Yovani Gallardo||Madison Bumgarner||Jake Peavy|
|Roy Oswalt||Chris Carpenter||Cole Hamels|
|C.J. Wilson||Brandon McCarthy||Adam Wainwright|
|John Danks||Cole Hamels||James Shields|
|Anibal Sanchez||James Shields||Matt Cain|
|Tim Lincecum||David Price||Matt Harrison|
|Tommy Hanson||Justin Masterson||Hiroki Kuroda|
|Hiroki Kuroda||Matt Harrison||Anibal Sanchez|
|Dan Haren||Josh Beckett||Jarrod Parker|
|Gavin Floyd||Tim Lincecum||Kyle Lohse|
|Mat Latos||Alexi Ogando||Josh Johnson|
|Chad Billingsley||Anibal Sanchez||Jordan Zimmermann|
|Matt Cain||Edwin Jackson||Jon Lester|
|David Price||Jon Lester||Madison Bumgarner|
|John Lackey||Derek Holland||Ryan Dempster|
|Max Scherzer||Zack Greinke||Trevor Cahill|
Ten players. I also imagine that several of those players slipped your mind if you were to make a guess at this list. Now, I used fWAR here, but you would get similar lists if you used other metrics life bWAR, FIP, ERA, wins, whatever. The names would slightly change, but the list would remain around 10 players. Players who consistently are in the top fifth of production (however you measure it) are quite few. Baseball is a hard game to be elite with performance and health. So, Chris Tillman has a difficult climb here.
Now, Tillman’s history as a pitcher has been one filled with promise and lackluster velocity. Only in the past year has he actually come forth and produced for the club where he has gone 18-5 with a 3.34 ERA. Those 18 wins are 4th best over the past calendar year (Chris does need to give some watches out to his offense which has produced 5.5 runs per game in those 31 outings). His ERA is 27th out of 82.
However, his peripheral statistics tell a slightly different story. His FIP (4.65) is 78th out of 82. His fWAR (1.7) is 71st out of 82. You might be asking why do these numbers differ so much from those above. Home runs are the main culprit. Last year, Tillman gave up two thirds (8) of his home runs with the bases empty. This year, it has been 76% (13) of his home runs this year. League average is 57%, so you can see that Tillman has greatly benefited by having guys go deep on him when the bases are empty. A metric like FIP and in turn fWAR (fWAR uses FIP) assumes that Tillman’s past performance with home runs is not likely to continue and future home runs will regress to the league average of expected runners on base.
The safe assumption is that a regression would be the case and, in turn, the home runs against Tillman will become worth more as more base runners will be on the paths. However, I am not sure that is the case. Even when Tillman’s performance was rather lackluster from 2009 to 2011, solo homers made up 69% of his batted balls that left the yard. This is beginning to make me think that from the stretch, Tillman may actually be turning into a different pitcher. Perhaps, his mechanics are slightly more consistent and he does not ride as many balls higher up into the strike zone. Therefore, the assumption that FIP is using may applicable to the pitching population in general, but perhaps not to Chris Tillman.
If this idea is actually accurate, then FIP and fWAR should not sour us as much as it might in our assessment of Tillman. However, it is still pretty difficult to thing of Tillman as an ace outside of looking at wins. His ERA, while good, has not been especially elite. Additionally, there are a couple peripherals that concern me. His fastball velocity has dropped from 92.4 to 91.7 mph. Currently, the velocity plays, but his past makes any drop a concern. Mechanical adjustments were able to save him the first time to resurrect his career in reclaiming that velocity, but we do know that his performance erodes along with any drop in velocity. Additionally of concern to me, last year Tillman was able to get swings and misses 8.1% (58th out of 88, if he qualified) of the time and that has dropped to 5.8% (95th out of 98). As one would expect, if a batter is more likely to make contact on a pitch then it is more likely something bad will come from it.
So what is the answer? Is Chris Tillman an ace?
No, I cannot think of any reason to call him that or to think that one day he could be called that. He has won a lot of games over the past year, but it is hard for me to lay those wins completely on his shoulders when the rest of the team winds up mashing the ball in his starts. Wins simply are not a great tool to measure the ability of a pitcher. They are not awful, but there are plenty better ways to measure performance. ERA suggests that Tillman just got into the top third of qualified pitchers. FIP suggests he is one of the worst qualified pitchers. When you take those together along with Tillman personal characteristics with regard to home runs, I think you wind up with a player who is probably a 3rd slot pitcher on a first division (read: playoff) team.
Tillman is still young and could become something more than he is right now. If he is able to generate more swing and misses, then a rise to being league average with that could turn him into a top of the rotation kind of arm if he maintains his deviant ways of not letting batters club a long ball when there are base runners. That said, I think he has way too much distance to cover to make it to being an ace pitcher. I would not call it a 0% probability, but it is likely close to that.