Kelly Shoppach has the unenviable task of replacing Jason Varitek in Boston. While Jarrod Saltalamacchia last year had arguably the more important job -- that of making up for the lost production of departed free agent backstop Victor Martinez -- Shoppach has to replace the catcher who was part of two World Series teams, was the club's captain, and caught in Boston for 15 years. That's a huge pair of intangible shoes Shoppach is trying to fill.
Turns out, though, that Shoppach might have problems replacing Varitek on a production level, too. As was discussed here after Varitek retired, he scores very well in terms of preventing runs in the newer advanced catcher defense research:
Since 2008, Varitek ranks fifth among catchers in runs prevented due to game calling and framing. [Dan] Turkenkopf wasn't kidding when he said that game calling is the "biggest single aspect" of catcher defense, as Varitek has prevented 57 runs more than expected in that four-year stretch.
...The gap is expressed in wins, even on a season-to-season basis, never mind cumulatively over four years. We can build a rough sketch of catcher defense using the numbers [Max] Marchi has produced for blocking pitches, game calling, and pitch framing and combining them with the figures of your standard defensive metrics that measure the ability to throw out runners and field the catcher position in the most basic ways.
...It's a rough sketch, but whereas Varitek was considered worth -3 runs by FRAA from 2008-2011, when combined with Marchi's figures, he's worth nearly six wins in the same stretch.
If you're into the idea the of advanced catcher defense including things like run values for the ability to frame pitches or call a game, then you might not be thrilled with Shoppach. He's solid at throwing out baserunners, and has no problems fielding the position in terms of batted balls, but that's about where that ends -- essentially, he's good at the things Varitek was not, and does poorly in the areas Varitek excelled.
Whereas Varitek prevented 57 runs more than expected due to game calling, pitch framing, and blocking, Shoppach was 51 runs worse. As he was worth a little over five wins the last four years without that information added, that means he was just a bit better than replacement level once the two cancel out.
There are caveats, of course. This research, while headed in the right direction, certainly isn't final. It could turn out that the effects are smaller than believed, and Varitek was actually just worth an extra three wins or so instead of nearly six, and that the same shrinking makes Shoppach fit the criteria of the perfect backup, lefty-mashing backstop. These sabermetric ideas all tend to start big, and shrink down as we refine them, as we learn more and more about how to properly measure the events we see in games.
Varitek would still get the extra credit due to him defensively as our idea of catcher defense evolves, and Shoppach would be properly penalized -- we're just not at the point where we can say that with any authority. We aren't even there with wins above replacement yet, or for defense at positions infinitely less complicated than that of catcher-- we've got a long way to go, but you have to start somewhere. We've got enough to go on where we can say that Varitek is a better defensive catcher than Shoppac, though, even if we can't say by exactly how much.
Shoppach should fill his role fine. He mauls left-handers (909 career OPS against southpaws), and his recent production in Tampa Bay looks worse than it is thanks to hitting in that domed canyon -- except for his defensive value, which spiked in 2011. He's keeping Ryan Lavarnway's seat warm while the prospect figures out how to handle a pitching staff on a consistent basis down in Pawtucket. Shoppach costs just $1.35 million, and is here for just the one year -- he might not replace Jason Varitek run for run, but that's not in his job description, either. Especially with Jarrod Saltalamacchia likely to be worthy of even more playing time in 2012.