JASON ROSENBERG: "Let’s just say that over the last thirty years, there have been essentially three truly dominant pitchers, at least as measured by ERA+."

WITH THE DAWN OF THE NEW YEAR COME...ROTATION COMPARISONS Domenic L. of Sliding Into Home takes the first crack at comparing Boston's rotation to New York's. Domenic does note the obvious: "The Yankees will not enter the season with Nova and Mitre, Brackman, Phelps, or another rookie at the back of the rotation. Even so, they would need a fair upgrade to match the Red Sox." But it may be worse than suspected.

Friend of the blog and Red Sox researcher extraordinaire, Ted Fischer, peered at the numbers and discovered that opposing hitters had much more success at the plate when Victor Martinez caught than when Jason Varitek or Kevin Cash were behind the plate. To wit, the below chart shows Opposing Batter OPS for Red Sox starters by catcher:

*Others include Varitek, Cash, Jarrod Saltalamacchia, Dusty Brown and Gustavo Molina.

Reviewing Boston's rotation from 2010, only Clay Buchholz and Josh Beckett did measurably better when Martinez was behind the plate. And both get qualifiers. Buchholz through to Martinez almost exclusively. And Beckett was pretty terrible. Daisuke Matsuzaka was erratic with Martinez catching him, authoring three gems, and failing to get through six innings six other starts. But in more innings to other catchers, Matsuzaka held opposing hitters to a better OPS than Jon Lester did throwing to Martinez. Even Lester who was positively ace-like all season showed a significant improvement with a different catcher than Martinez. And John Lackey was the pitcher Boston thought he was when they signed him in the innings he pitched when Martinez was not catching.

Using the more traditional metric of ERA, the Red Sox as a team had a team ERA of 5.11 when Martinez caught and a 4.20 ERA when someone else did. The peripherals like K rate (7.3/9 IP with V-Mart vs. 7.6/9 IP with the rest) and hit rate (8.8/9 IP vs. 8.5/9 IP) also favored the field. Home run rate (21.1/200 IP vs. 30.1/200 IP) and walk rate (3.1/9 IP vs. 3.7/9 IP) favored Martinez.

The data suggest Boston decided to move away from V-Mart to benefit their pitchers. They did so with an operating theory that the improved performance of their staff would make up for the loss of offense. Besides offense could be made up for elsewhere. If their theory holds, then the comparison being made is off by an order of magnitude at least. While New York is not done, Boston completely altered their paradigm. Their strategy may not matter at all - performance on the field counts, not spiffy theories - but it deserves consideration and discussion.