November 9, 2004
Time to Get PADE Again
Park Effects on Team Defense
Now that baseball’s coaches and managers have weighed in on their favorite defensive players, and Clay Davenport has unveiled his champion glovemen of 2004, I though I’d bring back an old friend for a fresh look at this year’s defensive performances.
Last year, I introduced some changes to Bill James’ Defensive Efficiency, a metric that measures the percentage of balls in play that the defense converts into outs. While it eventually ended in a measure intended to be free of both park and pitching factors called Team Adjusted Defense (TAD), I’m uncomfortable with the process of removing pitching from the operation, so for now I’ll stick to the original update: Park Adjusted Defensive Efficiency (PADE).
There will be one major improvement over last year’s version. In 2004, PADE will include instances in which a player reached on an error against the defense. For long and drawn-out reasons from which I will spare you, PADE missed that last season, but now it has been added and the metric is more accurate for it.
The first thing PADE does is generate defensive park factors for each ballpark. These will be slightly different from full park factors since defensive park factors do not include home runs. Instead, by comparing how each team plays defense at home and how they play it on the road, we can gain an estimate of how difficult each park is in which to play defense. These will be three-year factors to eliminate some of the variance for year to year with the obvious exception of the parks that have been open less than three years in Philadelphia, San Diego, and Cincinnati.
Here are the 2004 defensive park factors. The lower the factor, the more difficult it is to play defense:
Ballpark Park Factor SBC Park .9780 Coors Field .9796 Sky Dome .9857 Fenway Park .9861 The Ballpark at Arlington .9882 PNC Park .9898 Shea Stadium .9908 Metrodome .9954 Edison Field .9957 Jacobs Field .9961 Kauffman Stadium .9980 PETCO Park 1.0025 BankOne Ballpark 1.0038 US Cellular Field 1.0060 Wrigley Field 1.0139 Citizens Bank Park 1.0150 Turner Field 1.0152 Yankee Stadium 1.0152 Comerica Park 1.0157 Minute Maid Park 1.0162 Olympic Stadium 1.0164 SafeCo Field 1.0208 Busch Stadium 1.0233 Tropicana Field 1.0238 Dodger Stadium 1.0250 Camden Yards 1.0251 ProPlayer Stadium 1.0255 Miller Park 1.0262 Network Associates Coliseum 1.0312 Great American Ballpark 1.0371
There is quite a bit of interesting movement on this list with another year of data and the adding of reaching on errors. For example, SBC Park actually comes out as a more difficult venue in which to play defense than the vast expanses of Coors Field. I would assume that most of this is due to the staggering size of the outfield in SBC Park, the high wall in right, the small foul area, and the age of the Giants' outfield. Perhaps the San Francisco outfielders have a more difficult time than younger players compensating for the extra area in the outfield by the Bay. None of these reasons are actual explanations, but they seem the most plausible at first glance.
Also interesting is PETCO Park’s very average park factor despite the vast protests from many San Diego players about the park's ability to suppress offense. It’s just one year of data, but it appears at this point that PETCO’s main offensive suppression comes from turning home runs into very long flyball outs, making things easier on the defense, but much harder on Padres hitters’ agents.
Getting on with things, let’s see how teams fared this year. Here are the raw Defensive Efficiency numbers and PADE. PADE is presented as a percentage. For example, a PADE of 1 means that a team converts 1% more balls in play into outs than an average defense, given their park environment.
Team Def_Eff PADE Dodgers .7147 1.548 Cardinals .7126 1.398 Giants .6957 1.302 Mets .6964 .912 Red Sox .6944 .879 Phillies .7040 .829 Blue Jays .6934 .792 Marlins .7033 .405 Padres .6949 .352 Mariners .7009 .325 Cubs .6980 .271 Devil Rays .7013 .264 White Sox .6955 .292 Rangers .6879 .150 Expos .6964 .027 Pirates .6871 .013 Angels .6883 -.072 Twins .6876 -.132 Rockies .6809 -.252 Athletics .6982 -.287 Indians .6855 -.367 Braves .6901 -.558 Brewers .6922 -.715 Yankees .6883 -.736 Astros .6871 -.889 Diamondbacks .6825 -.930 Tigers .6859 -.991 Orioles .6871 -1.182 Royals .6766 -1.323 Reds .6896 -1.324
As expected, while there’s a little bit of shuffling in the middle, there’s quite a bit of movement at the extremes. The Reds, as a virtue of their venue, suddenly and narrowly pass the Royals as baseball’s most defensively inept team. Conversely the Rockies, as usual, move up to near average defensive performance.
What I found most interesting, however, was that the Dodgers and Cardinals--baseball’s two best defensive teams--managed to hold their top spots despite park factors that suggest some of their prowess is a result of friendlier confines than other teams. Also, despite some of the more well-publicized gaffes of the post-season, the Red Sox come out in the top tier of defenders. If the Sox’s braintrust truly was focusing on defense this season they accomplished their goals, as Boston’s new World Series champions flashed a great deal more leather than could have been expected.
The rest of the playoff field seems to run the full range of defensive ability as the Cardinals, Dodgers and Red Sox finished well ahead of the pack while the Yankees, Astros and Braves finished well behind. With the Angels and Twins both slightly below average, we can chalk up another point for those who feel that defense isn't a good predictor of who will reach the playoffs. However, considering how well the Cardinals and Red Sox did in October with their superior defenses, the idea that defense wins in the playoffs could be argued. Of course, considering some of the "defense" we witnessed in these playoffs, it's tough to say that that had anything to do with who won the games.