Verlander Versus Shields

A reader sends a question about Justin Verlander of the Tigers and James Shields of the Rays:

With all the talk about Verlander getting Cy Young and possibly MVP, I'm wondering how much better he's been than James Shields of the Rays.  Shields has a 2.70 ERA in a harder division (Verlander doesn't have to face explosive Red Sox and Yankees offenses as much as Shields), with 11 bullpen saving complete games, and 15 wins despite the anemic Rays offense.  Verlander has a gaudy amount of wins and 2.36 ERA in the AL Central, but could it be reasoned that Shields would have a better season if him and Verlander traded places?

It's a great question, but let me look at it another way.  When you look at the two pitchers in terms of opposition batting, Verlander is clearly superior.

2011	Verlander	Shields
IP	236	226.33
OBP	0.243	0.267
Slug	0.333	0.372
wOBA	0.252	0.277
BABIP	0.230	0.247
Strikeout %	0.265	0.227

Shields doesn't really save the bullpen any better than Verlander, since Justin pitched more innings this season.  On top of that, with the Tigers closer perfect on the season, there's no reason to avoid going to him in the ninth.  Verlander avoids the underbelly of the bullpen, and that's all a starter needs to do.

On top of that, Justin's averages are lower across the board.  Both pitchers record few hits on ball in play (BABIP), and that helps both tremendously.  One could argue, however, that Verlander received a few more lucky bounces.

That could be a big factor.  Verlander may be facing weaker hitters in the AL Central, or those hitters could just have suffered bad luck facing Verlander.  Let's look a little deeper, as PITCHf/x allows us to see in some ways the quality of their pitches:

2011	Verlander	Shields
Swing %	0.468	0.475
Pct Missed	0.237	0.246
% In Zone	0.428	0.515
Chase %	0.313	0.323
Called Strike %	0.359	0.327
Line Drive %	0.134	0.183

Note that this table paints a slightly different picture.  Shields gets more batters to swing, and more to miss when they do swing.  He tends to hit the strike zone more often than Verlander, and gets more batters to chase pitchers outside the strike zone.  In other words, in categories that measure the quality of the pitcher, Shields seems to be better.

That doesn't hold up everywhere, however.  Verlander gets more called strikes, meaning he tends to fool batters more.  A lower number of balls in play as line drives also implies Verlander fools batters, as that could lead to poor contact.

Or it could be that batters just can't see the ball.  Verlander's fastball averages 94.9 MPH, one of the fastest in the league.  Shields is down at 90.8, so he needs to be finer than Verlander.  My verdict is that both are aces, but in 2011, Verlander's ability to strike out more batters and catch them looking leads to his better numbers.  He more than deserves the Cy Young award.