If you’ve been to more than one Major League Baseball game, you might have noticed that the fields vary in size. Not the diamonds, those have very specific dimensions. But beyond the diamond, the size of the outfield and beyond can vary wildly from ballpark to ballpark. The history of why baseball fields vary so much at the professional level is partly historical, partly practical.

Read on for an in-depth look at why Major League Baseball fields aren’t standardized.


At the start of baseball as a professional sport, outfield fences didn’t exist. The rules themselves were still being argued about, so things like out-of-the-park home runs weren’t thought of. At the time, the ball was always retrievable. The outfield didn’t really ‘end.’ But as the game developed, fences were needed to keep the audience in place.

As sports rise up out of the dust, it’s expected that regional differences will become major points of contention. In baseball, the diamond itself is the central focus of play, and the outfield is usually a bit of an afterthought. It’s easy to see this in practice if you look at historical pictures of early games – people are practically sitting on the game-field itself!


However, even as these standardizations came into play, each park had its own physical limitations on the field size. Fenway Park, for instance, has a shorter left-field because of Landsdowne Street. As one of the biggest and most notable locations in baseball, the league had a decision to make: standardize to the smaller left-field size, the Green Monster included, force Fenway to rebuild or buy up an entire street – or accept that every baseball field has its own unique space.

For simplicity’s sake, it was decided that Major League Baseball parks would have a degree of freedom in the sizes and shapes of their fields. Some fields have very particular designs for different reasons:

  • Coors Field lays in Denver, one of the highest cities in the nation – compared to sea level. This means the city has lower air pressure, leading to many further hits. The Coors Field walls are set further back as compensation.
  • The Red Sox added a bullpen to their right-field, shortening the distance to the right-field fence. This was a bit sneaky, allowing their star left-handed hitter to have an easier time hitting home-runs.

In general, the unique nature of varying field sizes and shapes adds depth and complications to the drafting, lineup, and signage of players for the home team. This is just one way that the sport of baseball is unique.