I’m not sure who started it (perhaps Rany Jazayerli?), but a few years ago many internet writers began to call Gregg Zaun the Practically Perfect Backup Catcher. However, as people looked more closely. they began to realize that a catcher who was close to league average offensively (Zaun has a career 94 wRC+) and non-horrible defensively would actually make a Pretty Good Starting Catcher. The Toronto Blue Jays noticed and were the only team to really give Zaun a full season of playing time in 2005. By that time, Zaun was in his mid-30s, durability issues started to set in, and he’s never seen that much playing time again. However, the nerdosphere’s like affair with Zaun continued, and although he’s been more of a half-time player since then, he’s hit well enough to be an above average player (relative to his playing time).
Zaun’s 2010 with the Brewers ended early due to injury, and it’s an open question whether he’ll come back for his age 40 season in 2011. But there may be a new candidate to take up his role: Atlanta’s David Ross. Of course, barring unforeseen circumstances befalling Brian McCann, it makes sense that Ross isn’t going to be a starter in for the Braves any time soon. Despite his backup role, however, it seems to me that he could ably start for someone.
Ross has a good defensive reputation, and both DRS and TotalZone rate him as above-average. But let’s leave that aside and focus on his bat. We know that that most catchers don’t hit well. One of the handy things about wOBA is that it is just linear weights in rate-stat form, so we can convert it to runs above/below average. At FanGraphs, the full-season positional adjustment for catcher is +12.5 runs. So prorated 700 PA, to be average a catcher has to be worth -12.5 runs or better to be average or better (assuming average defense). In the 2010 run environment (.322 league average wOBA), that means a defensively-average catcher with about a .300 wOBA will be league average.
How does Ross stack up? Over the last three seasons (2008-present), he has a .349 wOBA (.249/.369/.421), which clearly puts him above the .300 “average line” we set above, as well as better than many starters over the same period, some of are rightly considered to be good players: Russell Martin (.324), Carlos Ruiz (.323), Yadier Molina (.319), and Kurt Suzuki (.315). While Ross’s 2009 power outburst (.234 ISO) was likely far above his true talent, and he’s probably had a fair bit of BABIP luck the last two season (.341 BABIP in both 2009 and 2010 so far), Ross has also thrived on an very good walk rate (15.1% from 2008-present) due to his consistent ability to lay off pitches outside the strike zone. Of course, there’s a sample size issue here, as Ross hasn’t even had 500 plate appearances total the last three seasons. A good bit of regression (particularly for BABIP) is called for here. After doing so, ZiPS RoS projects Ross’s current true talent as a .322 wOBA hitter — about MLB average, which, as a catcher makes him an above-average player.
In a league where Bengie Molina and Jason Kendall have full-time jobs, one wonders why more teams didn’t offer Ross a bit more money and playing time when he was last a free agent. His .286 wOBA in 2007 probably didn’t help, and perhaps teams felt he couldn’t handle even a half-time workload. However, in 2006 he played almost as much and had a .386 wOBA. Whatever the case may be, we probably won’t get to see what Ross could do with more playing time. Not only is he playing behind McCann, but the Braves have Ross locked up through 2012 at a bit more than $1.5 million a year — a bargain given that Ross still been delivering them about a win a season in less than 200 PAs. If McCann does go down for a while, Atlanta knows they won’t suffer too much in the hands of the new Practically Perfect Backup Catcher Who Could Probably Be Starting Somewhere.