ROBERT SIEGEL, HOST:
This season in college baseball, the sluggers got their mojo back. Home runs are up 40 percent over the previous season according to the NCAA. and that is because new, streamlined baseballs were introduced this year. Joining us to explain what they did and how it works is physicist Alan Nathan, professor emeritus at the University of Illinois, the man behind the website The Physics of Baseball. Welcome to the program.
ALAN NATHAN: Thank you.
SIEGEL: How is the new NCAA regulation baseball different from the old one?
NATHAN: Well, the old one - if you were to hold it in your hand, you would definitely notice that the seams feel a lot higher on the ball than they do on a professional baseball - a Major League or a Minor League baseball. And that turns out to have a rather significant effect on the flight of the ball through the air - the air resistance or air drag, as it's called. And that raised-seam ball simply doesn't carry as far as a ball hit similarly with the Major League baseball.
SIEGEL: Now the college players are using what they call a flat-seamed baseball. And the same amount of force from the bat hitting this new ball and hitting the old raised-seam ball - what's the difference?
NATHAN: Measurements have been done. You know, for a typical ball on a home run-type of trajectory that might come off the bat, it may be a hundred miles an hour. It may be a 30 degree launch angle - maybe a 15- to 20-foot difference. Twenty feet is an enormous amount. It's the difference between, you know, a warning-track shot and something that makes it over the fence.
SIEGEL: Now, explain. This is a response - this change of the baseball is a response to an earlier equipment change to the bats. Four years ago, the bats were deadened. They have to be stamped with the letters BBCOR, or a batted ball coefficient of restitution. And the point there was to take speed and distance off of batted balls. Why was that done?
NATHAN: So there's a long, long history of this. Throughout the years, the non-wood or aluminum bats have gotten better and better, and the game really got out of balance. The scores of games were very high. Games were taking a lot longer to play, and the traditional balance between pitcher and batter was way upset in favor of the batter. So the feeling was that you had to do something about it, so they deadened the bats. And maybe they deadened it a bit too much because a lot of people were unhappy. Home runs fell. Run scoring went down. Batting averages went down. All the usual offensive statistics went down. And I think a lot of coaches felt that the game wasn't where they wanted to play it, and so they urged the NCAA to do something else. And the something else was changing the balls.
SIEGEL: So in this season when the NCAA men's baseball tournament is underway and the College World Series is not too far off, people are happy with the game and the balance between hitting and pitching?
NATHAN: People seem to be happy with it, and of course, we'll see once the College World Series starts whether the number of home runs goes up in a significant manner. As I like to say, science both giveth and taketh away. It tooketh away with the bats, and it gaveth back with the ball. So we'll see how it works out.
SIEGEL: OK. The College World Series, I should say, starts on June 13. Professor emeritus Alan Nathan of the University of Illinois and of the the website The Physics of Baseball, thanks for talking with us.
NATHAN: You're welcome. Transcript provided by NPR, Copyright NPR.
