How Do Homeruns in Japan Equate to MLB

That would be the Baseball Prospectus articles you're refering to. McNeil-san's book, refered to here, also appears to covers the topic pretty accurately.

But you ask for rough estimates. I guess that means unsubstantiated with data?

It seems to me that there are a number of factors that allow for more home runs in the Majors than in Japan. Shrinking stadiums with odd dementions in the Majors for starters, compared to growing stadiums, usually going in doors in Japan. Also, MLB players tend to use steroids and weights a great deal more than their Japanese counterparts, making home run production higher. On the other hand, the domed stadiums do tend to see a lot of home runs, regardless of the higher fences. Jim Allen has a theory as to why.

Will Matsui (Hideki) hit more home runs in the Majors? I think there's a posibility he will. With more high speed pitches in a "strength vs. strength" atmosphere, he's going to turn a few heads - and make or break the above statistical analysies.

Thanks, yeah I was raised in baseball as kind of old school although because I am into computers I embrace the statistical side also. I wanted to know from an old shool perspective. I think the measures are accurate, but some writers who use them don't take into account the human element like adjustment period and such. They equate it to sample size and such but they just don't take into account human factors sometimes. Thanks for the reference to the book.

Ah, then you'd like some of Jim Allen's work. While he doesn't do the great analysies of his "Guides to Japanese Baseball" any more, he does write about the human factor a great deal. This is a sample from one of his "Guides."