Pursuits

This $200 AI Will End Tennis Club Screaming Matches

The In/Out rig scans court lines and maps the ball’s path.

Meet the AI Tennis Ref That Can Be Bought for $200

Lock
This article is for subscribers only.

Visit just about any tennis club on a Saturday, and you’re likely to witness otherwise sensible adults losing their minds over line calls. Players suffer complete meltdowns as they hurl insults. Parents morph into brooding teenagers. Friends become enemies. Postmatch beers can undo some of the damage, but the shame and resentment linger for days.

More civilized times may lie ahead. French inventor Grégoire Gentil has designed a $200 GoPro-size device that can be fastened to any net post and detect whether balls are in or out with surprising accuracy. It’s called, reasonably enough, the In/Out. “I was born in Paris and raised on clay,” Gentil says. On clay, the ball leaves a mark, and he recalls many arguments over a blemish on the court. “It was the starting point of this, I would say.”