In the aftermath of Wladimir Balentien breaking Sadaharu Oh's 49-year-old Nippon Professional Baseball record -- Balentien has 58 home runs, breaking the record of 55 that Oh shared with Tuffy Rhodes and Alex Cabrera -- the league's commissioner resigned. The reason for his resignation is tied to the league switching baseballs without telling anyone. It has been suggested that Balentien’s record-setting mark is somehow in need of an asterisk due to the change in baseballs.
How different is the new ball?
During the 2010 season, the league announced that it would use a new baseball that would be more similar to the kind used in international play. Mizuno announced that the new ball would travel about three feet less than the one previously used. This does not sound like much, but it can greatly affect the number of home runs. Last year at Camden Depot, we assessed what could happen if the fences were moved out at Camden Yards. It appears that a distance of 10 feet changes the number of home runs by about 20 percent. A change of three feet would result in something closer to a 5 percent change.
How have home runs changed in the Central League over the past several years?
With the new ball, home run rates have returned to levels more similar before the switch in baseballs. With this in mind, Balentien's accomplishment should not be lessened by speaking of a juiced ball as the ball seems to perform similarly to historical ones. Also of note, the 2013 home run rate represents a 57 percent increase over last year as opposed to the 5 percent increase suggested in our study. This discrepancy may be due to the limited scope of that study or that distance is not the only thing that changes home run rates.
It may well be that, with greater distance on the flight of batted balls, starting pitchers are getting knocked out of games earlier. In 2012, 6.3 percent of games ended with no one relieving the starting pitcher. This year, complete games have decreased to 5.2 percent, which is similar to the 5.2 percent mark in 2010 before the ball was changed. With outs being turned into home runs, starters have to throw to more batters and may be nibbling at the corners, which would increase pitch counts and walks.
That could greatly affect a player's ability to hit a home run because the range of talent on a typical Central League team varies quite a bit. A team like the Hiroshima Carp employs excellent starters like Kenta Maeda, Randy Messenger and Yusuke Nomura. It is not hard to imagine any of those pitchers fitting in on a major league team. But pitchers like Jumpei Ono or Hirofumi Ueno, who logged several innings this season for the Carp, might find it difficult to be promoted to a Triple-A team in the States.
With starters coming out of the game earlier and lesser pitchers entering, the change in home run rates could be much greater than simple distance measurements would project.
What does all of this mean? One, Balentien's record is legitimate with respect to NPB's historical game. Two, home runs are likely a function of more than how far the ball goes. Three, a home run is not a home run is not a home run. During a period of time, there may be certain things that are specific to an era (e.g., type of baseball used) where population-based metrics become more important than simple counting stats. Having hit 31 home runs in both 2011 and 2012, it seems 2013 for Balentien might simply be more of the same.
Jon Shepherd runs the Camden Depot blog on the Orioles.