Unlike the States, catchers tend to have a greater responsibility in Japan. If a pitcher gets shelled, they're part of the reason. Likewise, if a pitcher does well, it's usually because they did a good job leading the pitcher.
Darrell Rasner hasn't found a lot of success in Japan. Rasner currently owns a 6.11 career ERA which works out to 71 earned runs allowed over 104.2 innings of work. He has faced a total 469 batters and given up 122 hits (13 homers) and walks 32 for a 1.47 WHIP. His BB/9 works out to 2.75 and his SO/9 to 5.7. Both of these numbers are actually higher than what he was putting up back in States (1.72 BB/9 and 5.05 SO/9 in the Majors).
A newspaper article recently pointed to Rasner's catcher as being a reason for the success he found during his most recent start that ended in a complete game victory. While I'm still on the fence with regards to how important a catcher is to the relative success of a pitcher, I thought it might be interesting to provide a table of catchers that have caught Ranser since he signed on with the team last season.
Catchers that have caught Rasner since 2009
So, just how important is a catcher to a pitcher's relative success?