Last night Westbay-san of japanesebaseball.com posted this into the comments section of a story about the Giants considering a switch to a six-man rotation (a situation they’ve avoided by sending Barry Zito to the bullpen). Just in case there are those who don’t always read the comments, I’m going to turn the “comment” into its own post.

At the time of the post I was surprised Westbay-san didn’t check in with an opinion on the subject, but now we know why. It’s because he was busy emailing Bobby Valentine about it.

Here’s the comment in full:

I thought I would pose the question of a 6-man roster to one who has experience in both MLB and NPB - Bobby Valentine.

My questions:

When you came to Lotte, didn’t you discuss going with a 4 or 5 man rotation?

If so, what changed your mind?

What are the barriers to increasing the rotation size in the Majors and/or lowering it in Japan? That is to say, are the rotation sizes of each league culturally set in stone?

His answers:

I’ve also tried a six-man rotation in the States and it seemed to work. What changed my mind here was the amount of off-days. It seemed that everyone was on a routine. They use those off-days to practice. And without the practice in between starts, they weren’t comfortable, so I stuck with the six-man rotation and I saw that the arms stayed healthier, the pitchers pitched longer in the game and they seemed to do just fine.

I don’t know that it’s culturally set in America. It’s pretty culturally set in Japan. You know, it’s gone from a four-man rotation in the States to a five-man rotation, so the culture didn’t keep it from changing.

There is a rock and a hard spot now in the States. Guys want to get their starts. They want to get their numbers. And usually, if you have a contract, you get to pitch a lot, and if you pitch a lot, then you get a contract. It’s something that America and MLB really has to deal with.

Thank you Valentine-kantoku for taking the time to give a thoughtful response.