Most sports fans associate March Madness with the NCAA college basketball tournament, but for me, the month is a crazy one due to the demands of my various writing positions as they pertain to spring training. For the third year in a row, I’m handling Fantasy Baseball Index‘s spring update coverage, delivering camp notes for all 30 teams plus updated depth charts, projections and dollar value rankings. The first batch, which is free to buyers of this year’s Index, went out on March 1; subsequent updates are available via a weekly subscription newsletter starting March 12. See here for details.
In conjunction with a long-weekend ski trip to Salt Lake City that had my lungs searing due to an onslaught of fresh powder, said update kept me from checking in here to note my two most recent Baseball Prospectus pieces. The first took a look at some recent work done by Tom Tango over at the Hardball Times, work which provided some support for what I found in my contribution to Will Carroll’s The Juice, namely that new ballparks and expansion can’t explain the rise in home runs that’s typified baseball’s so-called Steroid Era:
Now the estimable Tom Tango has added some support for that viewpoint, at least with regards to parks and expansion. Comparing matched sets of head-to-head plate appearances between hitters and pitchers in the same park against all other pitcher/hitter/park combinations, Tango found virtually identical changes in home run frequency (HR per contact PA) from 1987 to 1988, and from 1992 to 1994. That is, both the matching combo and the unmatched combo saw their homer frequencies change at comparable rates during the same periods, first from 1987 to 1988, when a one-year home run spike came and went, and then from 1992 to 1994, a span in which homer and scoring rates escalated to levels that would be common over the next decade.
Like me, Tango then turned his attention to the baseball itself as an engine for the rise in home runs, and to evidence found via the University of Massachusetts-Lowell’s series of tests back in 2000. But it appears he was a little off base when he tried to connect the ball’s compositional changes with some data pertaining to fly ball distances:
In Tango’s piece, he turns his attention to the ball as well, and to the UMass-Lowell testing in particular, focusing on testing director Dr. James Sherwood’s report of an 8.7-foot difference in flight distance between tested major league balls and minor league ones, which differ in the compositions of their cores. Extrapolating from data provided by Greg Rybarcyzk of HitTracker Online, Tango finds that, lo and behold, an 8.7-foot decrease would reduce home run rates to almost exactly where they were in the decade prior to the surge. A tidy little explanation for where those extra long balls might have come from, right?
Not quite. Tango implies that what took place may have been as simple as MLB and Rawlings, the ball’s current manufacturer, replacing balls made with a pure cork center (as specified for the minor league balls) with ones made with a compressed-cork center (a composite of cork and ground rubber, known as cushion cork or cushioned cork, which is part of MLB’s official specifications for the ball). In actuality, the cushioned cork center ball is decades old: according to information provided by the Spalding company (which manufactured the balls up through 1976), it was officially adopted in the major leagues way back in 1926. Oddly enough, the words “cushioned cork center” imprinted on MLB balls were removed in 1999, the year before the UMass report was published, although the report notes that rubber continues to be added to the pill, the innermost element of the ball…
Though rubber and cork are still in the pill, its exact composition appears to have changed over the past couple of decades. A team from Universal Medical Systems confirmed this last summer, when they compared computerized tomography (CT) scans of baseballs from different eras. Whether simply due to technological advances incorporated into the manufacturing process or a calculated desire to produce more home runs, the pill has increased in size and density over the years. And that’s without considering the aforementioned synthetic ring, or the increasingly synthetic composition of the yarn used to wind the ball, something a University of Rhode Island study identified back in 2000. While Sherwood and company continue to test balls on an annual basis for MLB and have even shown some teeth by criticizing the outdated specifications of the testing, they’ve remained conspicuously quiet as to the impact of the composition changes, to say nothing of MLB bulldozing its own published specifications.
Take a picture, kids — it’s not often a hack like me can legitimately find fault with the work of one of the field’s top researchers. Then again, Enrique Wilson did get a few hits off Pedro Martinez, and D.J Houlton has struck out Albert Pujols in their only two encounters. It happens.
On the subject of The Juice, elsewhere in the piece, I re-visited some data from my chapter regarding the evolution of ballpark fence distances during the 1990-2004 period. Updating through 2007 and combining the two leagues:
MLB 1990 2007 Change
LF 329.6 332.0 2.4
LCF 375.5 376.6 1.2
CF 404.9 404.9 -0.1
RCF 376.0 377.6 1.6
RF 329.1 329.3 0.2
With the exception of the teensiest of fractions for straightaway center field, fence distances have actually increased during the wave of building that’s put 21 clubs (including four expansion teams) into new ballparks. What has decreased during the time period in question — indeed, what may be confusing the issue — is smaller park capacities. In 1990, the average ballpark held 53,057 patrons; last year it was 48,219, a drop of about 10 percent. So yes, parks are smaller, but not in a way that carries any ramifications for home run levels.
Since this article’s publication, several readers have pointed out that while the fair territory of playing fields aren’t getting smaller, a decreasing amount of foul territory may be contributing to the rise in homers and scoring in general. That’s something I’ll be examining in my next take on this subject.
Whew. My second recent piece at BP is a pinch-hit job on the Texas Rangers’ Team Health Report, since Will Carroll’s commitments prevented him from taking a swing. I wasn’t able to bring quite the amount of background to the Rangers that I did to the Brewers’ THR, since I didn’t cover the former in the now-shipping Baseball Prospectus 2008, but I did discover that the Rangers led the majors in number of trips to the DL last year (23) and number of same which were pitchers (14). Those injuries didn’t cause the team’s 19-35 start in April and May; four missed Kevin Millwood starts didn’t hurt nearly as much as a 6.44 ERA from the rotation, but it sure didn’t help. Anyway, the Rangers’ THR is free if you’re inclined to check it out.
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The other element of my personal March Madness is promotional appearances for BP08. My ski vacation cost me a trip to the Yogi Berra Museum, but I’ve still got a handful lined up for this month:
• Thursday, March 6th, 6:00 pm, Barnes & Noble, 105 Fifth Avenue (at 18th Street), New York, NY 10003. With Steven Goldman, Derek Jacques, and Joe Sheehan
• Saturday, March 8th, 2:00 pm, Borders Books, 1260 Old Country Road, Westbury, NY 11590. With Derek Jacques and Joe Sheehan
• Monday, March 17th, 7:00 pm, Politics & Prose, 5015 Connecticut Avenue NW, Washington, DC 20008. With Clay Davenport and Steven Goldman
• Tuesday, March 18th, 7:00 pm, Barnes & Noble, Rittenhouse Square, 1805 Walnut Street, Philadelphia, PA 19103. With Steven Goldman and Joe Sheehan
If you’re nearby any of these, we hope you can make it out. Also, I’ll be hosting a chat at BP on Thursay the 6th at 1:00 PM for those of you burning to talk some baseball but unable to make it out.