Comparing (Jason) Castro: A Look at the Astro Catcher

I was surfing my RSS reader the other day when I saw this article on FanGraphs called "Comparing Castro." I immediately though, "Wow, they're talking about Jason Castro! I must go read this!" Unfortunately, the author, Bryan Smith, was referring to Cubs shortstop prospect Starlin Castro.

It dawned on me after reading the article that I could just do a very similar analysis on OUR Castro. After all, I have access to the wonderful Baseball-Reference Play Index. I have access to FanGraph's historical WAR data and I had some free time to play around in Excel.

The first thing that struck me is how few catchers made their debut at or before Age 22. I anticipated that the selection pool would be bigger than Smith's, since more players make their MLB debut at 22 than at 20. Turns out only 25 guys played at least 75 percent of the time wearing the tools of ignorance before they were 22. Only two played in more than 110 games, including Bob Didier in 1969 and Hall of Famer Mickey Cochrane. It's a rare thing to have a talented and young catcher, it seems.

The 25 catchers who debuted at 22 averaged 243 plate appearances and 72 games played. That number is inflated a little by the five guys who played over 100 games. The median number of games was actually 62, meaning most of the catchers in this group played about 40 percent of their team's games.

The group's average slash line is not promising (.254/.319/.355). The group also averaged nine doubles, two triples and three home runs. Averages like this aren't precise but give us a good starting point to jump deeper into the comps.

12 players had reliable minor league data that we could compare to Castro. Of those, only two had spent two years playing minor league baseball before making his debut (BJ Surhoff in 1986 and Mark Bailey in 1984). Most were drafted out of high school and had spent what amounted to a 4-year college career in the minors. Four others were drafted out of college and immediately rushed to the show, Craig Biggio chief among them. Interestingly, Biggio was not the only Astro on the list, as former bullpen coach Bailey, John Bateman and John Mizerock also made an appearance. 

As a refresher, Castro hit .300/.380/.446 in 511 plate apperances split between High A Lancaster and Double-A Corpus Christi. The minor league line for our 12 comparables? .290 batting average and .446 slugging percentage (because all but two of the comps were lacking plate apperance, walk, sac fly and hit by pitch data). We can then cut this list down more by eliminating all the players on the list with more than two years experience in the minors and players who played less than 100 games the season before their debut (often because they had just been drafted). This way, we have a set that can predict what he might do if given a starting job early in the season.

That leaves us with four potential candidates. Bailey, Surhoff, Jason Kendall* and John Bateman, who was a catcher for the Astros back in 1963. All four had at least 400 plate appearances in their rookie seasons and played at least 100 games in the minors prior to being called up.  Bailey and Bateman were not the hitters that Castro projects to be. Neither managed to hit over .281 the season before being called up, but both managed slugging percentages above .460 (which Castro lacks).

*I left Kendall in, even though he was a high school draftee, because of how similar their minor league numbers were. It was a judgement call, but I also didn't leave anyone out who had at least 400 plate appearances and played after 1960.

Also, Bailey played the 1983 season in the Class A South Atlantic League while Bateman played in the Class C California League. Surhoff spent his time in Triple-A and hit .308 with a .395 slugging percentage. Kendall was in the Double-A Southern League and hit .325/.414/.448 in 117 games.

Castro obviously has less power and hits for more average than either Bailey or Bateman, so we're left with Surhoff and Kendall as the potential comps. BJ Surhoff primarily played catcher for the first six seasons he was with Milwaukee. This surprised the heck out of me, because all I remembered him as was an outfielder with the Orioles. Using the same WAR historical data that Smith used, we can see that Surhoff was 10 wins better than a replacement catcher over those six seasons. His catcher rating bounced between +8 and -4 and was his main source of value, since he cost his team 35 runs over those six seasons with his bat. The majority of that disparity came in 1988, when he was -20 in batting runs.

As for Kendall, his bat was never the problem. His defense, on the other hand...Kendall has totaled 37.1 WAR in his 14 year career, but his catcher rating over that same time frame is -22. Despite having negative batting runs for the past six seasons, Kendall is still +12 for his career. That just shows you how good his bat was early on. His glove, on the other hand, was bad enough for the Pirates to put him in the outfield for 27 games during the 2001 season. While it's interesting that both players had some time in the outfield, don't expect to see Castro spelling Hunter Pence in right field any time soon.

We're left with a dilemma. One of our comps is a good bat, bad defense guy and the other is a good defense, bad bat guy. Somewhere in between lies Jason Castro's future. I'd argue that his defensive potential is better than Surhoff's was and his bat could be similar to what Kendall did his rookie season (.300/.372/.401). That makes him about a 2.0 WAR player. CHONE didn't see him that optimistically, listing him at 0.8 WAR. At the same time, teammate JR Towles IS listed as a 2.0 WAR player in CHONE, so what are we left with?

I wouldn't be surprised if Castro spends half the season in Triple-A gaining experience. Almost every player on this list of catchers who debuted at 22 spent some time there. It's a hard job with lots to learn. But, if his comparables are any indicator, Castro could see time as early as May and probably would be a very good player from the get-go. Players who are two wins above replacement-level are not All-Stars, but a 22-year old catcher who's a solid starter?

That's a very encouraging proposition.