Wiffle ball primerIt’s safe: Wiffle ball is a variation of baseball played with a long yellow plastic bat and a plastic ball with eight oblong perforations on one side of the ball. The holes on the ball help the pitcher throw curves, sliders, sinkers, screwball and risers without putting any stress on the throwing arm. Wiffle balls are easy on windows, and they are cheap: A box of 24 should last a kid all summer ($28.70 on Amazon).

It’s fun: It’s tough to play baseball without an umpire because so much of the game relies on an umpire’s calls. But no umpires are needed for Wiffle ball. If the pitch hits a chair behind the strike zone, it’s a strike; if it misses, it’s a ball. There is no baserunning. If the fielder makes a clean play of a fly ball or a ground ball in fair territory it’s an out. Otherwise, it’s a hit.

Advanced moves: Check out the pitches on wiffleboy28.com. Sean “Wiffleboy” Steffy has published an incredibly complete how-to guide for mastering Wiffle ball pitching. If you want to learn how to amaze your friends, or your kids, take some pointers from Wiffleboy’s videos.

Other Wiffle ball stadiums: Little Fenway in Essex, Vt. (littlefenway.com) and Strawberry Field Park in Encino, Calif. (strawberryfieldpark.com)

By Jeremy Kohler