Now that the trade deadline is almost here, baseball fans are excited to see who might be dealt, and what prospect might be had. Invariably, people are looking for the "impact bat" or the "ace pitcher." When we talk about an ace, though, people can have different definitions of the word. For some people, it might just be the best pitcher on their team:
"Bud Norris is the ace of the Houston Astros."
This implies that there are exactly 30 pitchers in baseball that qualify (and this season, Verlander isn't an ace because he's not the best pitcher this year).
For other people, it's just the 30 best pitchers in baseball.
"I wonder if the Orioles might deal for ace pitcher Eric Stults."
For most fans and pundits, though, ace is more of a nebulous definition. There are generally only a few players that qualify (say, as few as 5 and as many as a dozen), and the criteria is a blend of stuff and results. I thought it'd be interesting to use a few parameters and try to actually quantify "ace" material.
There are two main factors to determine an ace: you have to be durable and you have to be great. How do we quantify those numbers, though? First, I looked at the innings totals for 2012. I defined (and will define) durable as being 15th or better among innings pitched leaders (for 2012 [my focus for this article], it was 211 innings). That would mean that (for the era), you were as durable or better than the average pitcher that was the most durable on his team. The problem here is that you aren't always replacing those innings a starter doesn't pitch with replacement-level value. If you make 32 starts and pitch 160.1 innings, the innings you DON'T pitch are picked up by your bullpen (which may or may not be replacement level). To get around that, I made the following adjustment:
Any inning before 188 innings (the average number of innings a starter with 32 starts would log) was taxed at replacement-level starter FIP (which is 5.12), and any inning in between 188 and 211 innings is taxed at the reliever-average FIP (which is 3.79, actually).
So, what FIP actually defines greatness? I'd say it's whatever makes average look replacment-level (that is, whatever FIP carries an expected win percentage of 62% when set against the league average). In 2012, league-average FIP was 4.01. That left the value you'd need at 3.14. So, if you can provide 211 innings of 3.14 FIP baseball, you're an ace. You don't have to do exactly this: 199 innings at a 3.1 FIP is still an ace (the 11 innings you lack are made up for by the slightly better FIP you sport)
HOWEVER, this doesn't address something important. Every inning over 211 innings that a player pitches is another inning that your bullpen doesn't have to pitch. So, you should get a credit for pitching more innings than 211. In that case, you should be credited the difference between the pitchers' FIP and the average reliever (again, 4.01).
So, who was an ace in 2012? I have 8.
Justin Verlander
Felix Hernandez
Clayton Kershaw
Gio Gonzalez
Cliff Lee
Zack Greinke
David Price
Adam Wainwright
Stephen Strasburg*
*was an "ace when healthy (not enough innings to provide necessary FIP)"
That makes sense to me. The two closest non-ace pitchers were Wade Miley (194.2, 3.15), who was almost good enough FIP-wise but 16.1 innings short, and R.A. Dickey, who pitched a ton of innings (233.2!) but just wasn't good enough in those innings (3.27 FIP, still very good).
Let's take this a step further. What defines a #2? Let's say it's 45th in innings (so the average of the second best pitcher), which for 2012 is 191 IP. Furthermore, we don't expect him to make the league-average starter replacement level; let's make him 56/44 instead of 62/38. That brings the FIP to 3.55. If we plug that in, we get the following "true #2"s:
Wade Miley
R.A. Dickey
Johnny Cueto
Stephen Strasburg
Cole Hamels
CC Sabathia
Chris Sale
Yu Darvish
Max Scherzer
Matt Cain
Madison Bumgarner
James Shields
Josh Johnson
A.J. Burnett
Jordan Zimmermann
Kyle Lohse
Anibal Sanchez
Jarrod Parker
(Lance Lynn, Doug Fister, and Shark all just miss.)
That makes sense to me too. There are 8 true aces, and about 18 number 2s. The list isn't perfect, but I think it's very close and a worthwhile distinction to make (it also puts Shark into perspective).
One last thing; there is definitely an quality to an ace pitcher that is consistency (being excellent over a multi-year period). I'll perhaps look at that later; this is more of a snapshot sort of thing.
Comments
I like when math confirms our suspicions. Makes me feel all warm and squishy inside.
joshQuote Reply
Whoa, did B Jax just get demoted?
joshQuote Reply
Brett Jackson====> AA
He fucking sucks
bubblesdachimpQuote Reply
Three guys from the 1997 Cubs starting rotation are dead.
Kevin Foster – renal cancer in 2008
Geremi Gonzalez – struck by lightning in 2008
Frank Castillo – drowned in 2013
Steve Trachsel and Kevin Tapani remain. Terry Mulholland too – he was traded mid-season.
Aisle424Quote Reply
I thought he was rehabbing in the lower levels.
WaLiQuote Reply
@ WaLi:
he was stirking out in AZL a lot
bubblesdachimpQuote Reply
@ WaLi:
Was he hurt?
joshQuote Reply
@ Aisle424:
I have no memory of that team. I think because that was right after I graduated high school, so I was working at a summer camp where there was no TV.
joshQuote Reply
Interesting article, Myles. I’ve always just assumed ace = 30 pitchers since every team has one. I didn’t use current season stats, though. I went on history (projections) and know that while the 90s Braves had at least two or three guys at any one time that could be the best starter on another team.
dmick89Quote Reply
Aisle424 wrote:
Maybe they should lock themselves in.
dmick89Quote Reply
@ josh:
From July 21st
http://mlb.mlb.com/news/article.jsp?ymd=20130721&content_id=54330352&c_id=chc
WaLiQuote Reply
I don’t think it’s that surprising that a guy rehabbing is sent to different levels before returning to AAA. It happens a lot.
dmick89Quote Reply
josh wrote:
This. Also sorta gets to the heart of why I I’m pro-trading Spellcheck. I think he’s more valuable to a team like the Pirates, who already have a guy like Cole, than he does to the Cubs. But that may just be old-school thinking creeping into my reasoning. I dunno.
sitrick2Quote Reply
They were talking about sending Jackson down to AA before he got hurt anyway. Wanted to get his confidence level back up. But given that he was struggling in limited AZL time, things might be pretty dire.
sitrick2Quote Reply
dmick89 wrote:
This.
BerseliusQuote Reply
This was a great idea, Myles. Good post.
BerseliusQuote Reply
http://deadspin.com/espns-nate-silver-is-here-to-answer-your-questions-951328525
dmick89Quote Reply
Suburban kidQuote Reply
I thought I would ace it but I only got 36.
http://www.sporcle.com/games/notaratface/mlb-hitters-left-handed-or-right-handed
Suburban kidQuote Reply
New shit:
http://obstructedview.net/previews/series-preview-milwaukee-brewers-43-61-at-chicago-cubs-48-55.html
BerseliusQuote Reply