Finding historical comps for R.A. Dickey is a fool's errand -- he's a baseball unicorn. We have never before seen a 38-year-old pitcher who lacks an Ulnar Collateral Ligament and launches "power" knuckleballs toward home plate, looking like Leonidas the Brave while doing so. Will Dickey pitch far into his forties like the Niekro brothers, Tom Candiotti and Tim Wakefield, or will he fade faster due to his (relative) reliance on velocity with the pitch?
No one knows for sure, but Dickey showed no signs of slowing down during his Cy Young 2012 season. He put more zip on his knuckleball last year, greatly increasing his percentage of flutterballs thrown over 75 miles per hour and inducing lots of swings and misses with those pitches:
Distribution of Dickey's knuckleball velocity, 2010-12
Dickey threw about 87% of his knuckleballs at 75 MPH or faster in 2012, compared to about 73% in 2011 and 66% in 2010. His miss rate with those power knucklers was nearly 28%, up from 20% in 2011 and 21% in 2010. That's how Dickey boosted his strikeout rate from the mid-to-high fives in 2010-11 to nearly a batter per inning last season. He got most of those extra whiffs on pitches thrown at or above the belt. Check out Dickey's opponent contact rate on knuckleballs thrown at 75+ MPH in 2010-11, and then in 2012:
Dickey's opponent contact rate on 75+ MPH knuckleballs, 2010-11
Dickey's opponent contact rate on 75+ MPH knuckleballs, 2012
Batters swung through about 30% of Dickey's power knucklers thrown in the upper half of the strike zone, a marked increase from slightly under 22% in 2010-11.
We don't know whether Dickey will remain an ace-level pitcher for another couple of years or a decade. If 2012 is any indication, though, there's plenty of power left in his ligament-challenged right arm.