- FanGraphs Fantasy Baseball - http://www.fangraphs.com/fantasy -

Wilin Rosario: Most Profitable Catcher of the Year

As we sift through Zach Sanders’ end of season catcher valuations, we find a surprising name sitting at number five, having earned $12 (would be more in two catcher leagues). Well, not surprising given that we know how he performed, but surprising in that we didn’t even rank him as part of our consensus during the pre-season. Ramon Hernandez was supposed to receive the bulk of the backstop playing time for the Rockies, but he suffered a hand injury in late May that opened the door for rookie Wilin Rosario. When Hernandez finally returned, Rosario had already run away with the job.

Rosario’s performance wasn’t too surprising given his minor league stats. However, he never received an at-bat at the Triple-A level, so it was that much more impressive that he was able to make such a seamless transition to Major League pitching. Given Rosario’s power, his strikeout rate is acceptable, though of course he could afford to improve that part of his game. But with a SwStk% of 14.5%, which was the eighth worst mark in baseball among those with at least 400 plate appearances, he’s got work to do.

Some additional patience would be nice, as Rosario’s walk rate was rather poor. Amazingly, he still managed to score 67 runs in 426 plate appearances, despite posting just a .312 OBP. Unfortunately, his minor league walk and strikeout rates don’t portend any improvement in the near future.

Obviously, Rosario’s fantasy value comes from his power. Among those with at least 400 plate appearances, he ranked 9th in ISO and 5th in HR/FB ratio. And that’s as a rookie catcher! For nearly any hitter, except the rare cases where the player has consistently shown this type of power, you should expect regression the following year. That expectation will be no different for Rosario. Of course, how much is the question. He has a lot of room to decline since he was so good this year. And since he strikes out a lot, a precipitous fall will be quite detrimental to his fantasy value.

As usual, I have investigated the distance data on both his home runs and homers plus fly balls. The average distance of his home runs and fly balls was a whopping 308.6 feet. That ranked an amazing fifth overall among hitters with at least 50 flies + homers. Switching over to his ESPN Home Run Tracker data, his average standard distance on long balls was 404.6, which is very good, though not as impressive as the value that included fly balls. Of his 28 home runs, 10 of them were classified as “just enough”, which represents a slightly higher percentage than the league average.

From the data at these two sites, it’s pretty clear that Rosario has serious power. And although he loved Coors Field like most hitters do, he still ISO’d .206 in away ballparks, and posted a 19.2% HR/FB ratio. In Coors, he had a video game-like .312 ISO and 31% HR/FB ratio. He’s still in Coors next season, so his home/road splits don’t really mean much when projecting him for next season. The good news is that he still has good enough power in away games that you don’t have to worry about benching him if you’re in a daily league.

Looking toward 2013, I would expect Rosario to receive more at-bats given that he’s now going to open the season as the de facto starting catcher. The percentage play is to expect some decline in his power numbers, but I have to think that he should be a lock for at least a mid-to-high teens HR/FB ratio. That might not sound so bold, but given his lack of experience, both from skipping Triple-A and garnering just 450 Major League at-bats, I simply cannot project him to be one of the best power hitters in baseball just yet. The additional at bats though will help his counting numbers and should offset some of the decline in his power rates. His BABIP should also climb a bit, so his batting average might not fall too far if some additional fly balls are now caught rather than going over the fence.