Ballpark Playing Surfaces Are Shrinking in a Surprising Way

Back in April, this author argued that the new generation of ballparks is pushing us (well, some of us) away from the game.

The retro-ballpark era has been universally praised for bringing wider concourses, greater amenities, and generally more charm to major-league facilities. However, many of these parks suffer from a significant flaw: by removing obstructed views and adding layers of luxury suites, clubs have pushed fans in the upper decks — that is, the middle class of fan — further away from the sights and sounds of the playing surface.

While the move away from the cookie-cutter, multi-purpose stadiums of the 1960s and 70s is undoubtedly a positive one for the fan experience and while the actual ballparks of the past featured a number of design flaws themselves, not everything is ideal with this new generation of ballparks.

Consider: even as fans in the bleachers and upper deck have been further removed from the action, the installation of lower-deck seats has brought some folks closer. To get a sense of what I mean, consider the evolution of Dodger Stadium through images of the park from 1962, 1969, 2000, and 2014, paying attention in particular to the area along the border of the playing surface.

While the fairness of this trade-off is perhaps questionable, that particular concern is a consideration for another time. What’s relevant about this development in terms of the present post is the effect of that new seating on the game.

Playing surfaces of the new generation of parks have generally contracted in size. There appears to be little argument about that — and the data supports it. The trend is thought to have played a role in the increasing rates of home runs due to tighter ballpark dimensions. Yet the new-age stadiums are shrinking in a way you might not expect — or, certainly in a different way than I suspected.

To see how parks have changed relative to their predecessors in terms of on-field square footage, I revisited Andrew Clem’s excellent website, which I also consulted for the aforementioned article.

Using Clem’s data, I was able to find fair and foul territory for 21 current major-league stadiums and their immediate predecessors (or pre-renovation versions of themselves). Note: all 30 current MLB stadiums have fair and foul territories listed at the website, but not every defunct park has square footage listed.

It was interesting to see how the playing surfaces have shrunk. The square footage of fair territory in the 21 parks considered has diminished by only 1.4%. I would have suspected it had decreased more dramatically. The real change has occurred elsewhere, however: foul territory has diminished by 20.5%, or about 5,500 square feet on average.

Consider the following table (with data from Clem’s site):

While many suspect both fair and foul territory have contracted, this author thought the percentage change of fair territory would have been greater. But it is actually foul territory that is shrinking dramatically.

We know that foul territory has shrunk — in particular as designers of new-age stadiums have been freed from the demands of multi-purposes considerations. The result, unsurprisingly, has been to push field-level seats closer to fair territory. At places like Dodger Stadium and elsewhere, teams/owners have added additional rows of lower-deck, luxury seating, further eroding foul territory. “Field boxes” have crept closer and closer, which is great if you have netting between you and the action. And with more and more teams taking up MLB on its recommendation to expand netting in front of lower-deck seats, it could allow for more premium seats to be added and for foul territory to diminish. Hey, netting could hypothetically allow for something like courtside-style seating in the majors.

For hitters like Mike Moustakas who have double-digit infield fly-ball rates, this is a positive development: it allows a portion of routine outs to be avoided and for at-bats to continue. At the same time, it’s making the life of a pitcher just a little more difficult. A 20% reduction in foul territory from one generation of parks to another seems significant, while the fair territory appears to remain relatively unchanged.

The new generation of ballparks is pushing some of us away and bringing some of us closer. And it is the new generation of ballparks that is also shrinking the playing surface — which we knew — but maybe not quite in the way we expected.