Major League Baseball’s season was supposed to start last week. Fans should already be stuffed with $8 hot dogs, $12 beers and jokes about the New York Mets. But Opening Day was postponed because of the coronavirus pandemic, and it isn’t clear when the season will begin—if it ever does.

Still, one thing is certain: with every day that passes, the 2020 season gets shorter and shorter. And while it may be impossible to know exactly what MLB’s season will look like, it’s possible to answer a slightly different question: How...