Why do baseball fields have a checkerboard pattern in the outfield grass?

Dear Cecil: The spring breeze is blowing, and it’s starting to smell like baseball, at least here in Texas. This brings to mind a fundamental question: how do groundskeepers make the checkerboard pattern in the outfield? Alternating types of sod? I’ve always wondered. Justin Gaynor, Dallas

Cecil replies:

For the answer to a classic question, you want a classic source. For my money, you can’t do much better than the groundskeepers at Wrigley Field, home of the Chicago Cubs. (I tried Fenway too, but they didn’t answer the phone.) The members of the Wrigley crew take their work seriously because they know that after a few innings of a typical Cubs game many fans won’t be able to bear the sight of the game anymore and will want to turn their gaze to some less exasperating scene, such as a few choice acres of God’s green grass. Thus the checkerboard.

Roger Baird, assistant Wrigley GK, says he gets on his 82-inch riding mower and on day one mows east to west and on day two (or the next time he cuts the grass) north to south. He follows precisely the same path every time, mowing east in the east rows and west in the west rows and so on, always taking care that today’s rows (swaths, whatever) exactly line up with those from previous days.

If you’ve ever tried the same stunt with a vacuum cleaner on a rug, you know what you get: a checkerboard of squares roughly 82 inches on a side. The grass in a square mowed west and north will catch the light differently from one mowed east and south. It doesn’t help the grass grow better, it doesn’t align with the earth’s magnetic lines of force, but it does look pretty cool on color TV.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.