An "Ace" in the Hole

One of the recurring themes I had to deal with in evaluating rosters for our season previews was how to define an ace. Additionally, as I was watching Justin Verlander pitch last night I was struck with the notion that while Verlander isn't a poor pitcher by any means, he might not be one of the true 'shut-em-down' aces that teams rely on. Obviously, Verlander is the ace of the Tigers rotation. That being said, being tabbed as a number one starter doesn't necessarily mean you are a good pitcher (Luke Hochevar) or even the best on your team (Ian Kennedy, Mark Buerhle).

If wins were the measure of an ace then Verlander would be in the discussion as he has won 17 or more games in four of his five seasons. Indeed, only Roy Halladay (90) and C.C. Sabathia (88) have won more games since Verlander entered the league. However, if you look at adjusted ERA (ERA+) over that same span for pitchers with more than 600 innings pitched during that period then Verlander slides to 20th in baseball.


After watching Tim Lincecum and Clayton Kershaw battle it out last night, where both pitchers went 7 innings without allowing any earned runs, it dawned on me that a true "ace" is a pitcher that churns out these kind of starts on a regular basis. This moves beyond another meaningless stat, quality starts, and ups the ante a bit.

Let's call this an "ace" start: 7+ IP and 1 or less earned runs. I would consider this an excellent outing that puts any team into a good position for the W. Let's use the last five years as a sample to match up with Verlander's career...

Player	#Matching(% of starts)
Roy Halladay	57 (35%)
CC Sabathia	56 (34%)
Felix Hernandez	54 (34%)
Johan Santana	47 (30%)
Roy Oswalt	45 (28%)
Bronson Arroyo	45 (27%)
Tim Lincecum	41 (34%)
Cliff Lee	41 (29%)
Dan Haren	41 (24%)
Matt Cain	41 (25%)
Jake Peavy	40 (32%)
Wandy Rodriguez	39 (27%)
Justin Verlander	38 (23%)

There aren't any real surprises here. The only adjustment that would need to be made would be Lincecum, who has only started 122 games during this period, whereas all the other starters are generally around 160 starts. Jake Peavy and Johan Santana also eclipse the 30% mark but injury concerns have placed them outside the conversation of aces during the past year.

That would put Halladay, Hernandez, CC, and Timmy as the top 4 in baseball over the past five years, which would sound about right. After those four you get into a group of really good, top of the rotation starters, that are also capable of generating "ace" starts, but not quite at the rate of the games elite.

Thoughts? How would you define an ace?