SABR 35 - The Green Monster Effect: a run saved or a run earned? (Research Presentation)
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| By The SABR Office |
The Green Monster Effect: a run saved or a run earned?
Noah J. Kaufman and Jesse Gerner
King II
We are interested in quantifying the effect of parks on players’ defensive statistics. This project specifically examines how outfield dimensions affect run scoring opportunities, and the subsequent related defensive metrics.
In undertaking this project for our Tufts University baseball sabermetrics course, we were initially piqued by Clem Comly’s research in Average Run Equivalent Method (ARM) (see By The Numbers, August 2000, p.11-15), which implemented expected runs matrices to quantify runs allowed and runs prevented by the strength, or perceived strength, of an outfielder’s arm. Interested by his observation that the top two left fielders (as measured by ARM rating) were Carl Yastrzemski and Jim Rice – both of the Boston Red Sox – we decided to study the effects of Fenway Park’s left field.
Fenway’s leftfield wall, The “Green Monster,” has consistently ranked among the shortest fences down the line of any major league ballpark (and has subsequently led to Fenway’s frequent labeling as a “hitter’s ballpark”). Because of its height, the wall often forces left fielders to play twenty to forty feet shallower in anticipation of balls hitting the wall and ricocheting back towards the infield. We thus hypothesized that Fenway’s leftfield and the Green Monster result in fewer runs scoring on singles to leftfield, thus causing the park to favor, at least in some situations, the defensive team.
We analyzed a randomly chosen ten-year period of over 19,000 major league games, using Retrosheet data. Using game situations involving runners on second base, we quantified and compared run scoring instances at Fenway Park to other major league stadiums. The proportion of runners attempting to score from second base at Fenway was significantly less than other parks (p<0.05, chi-squared analysis). We also used linear regression analyses to explore the relationship between ballpark dimensions and a team’s ability to score runs. All data manipulation and analyses were conducted with SPSS statistical software.
Our results show that not all ballparks are created equal. While on an individual basis certain players may have better arms than others, the park in which they play is just as important in preventing or allowing the scoring of runs. Such park-specific information could prove valuable to the front office executives looking to gain further insight into situational effects and park impacts. These findings all contribute to what we hope will prove to be the sabermetrician’s ability to uncover the true effects of variations in ballpark design throughout baseball.
NOAH J. KAUFMAN and JESSE GERNER are students at Tufts University in Medford, Massachusetts.
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| | Created On: 2005-07-12 |
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Page Link: http://www.sabr.org/sabr.cfm?a=cms,c,1330,34,0
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