The underarm serve: tennis's most controversial trick shot. While some players swear by it, others swear at it. But when executed perfectly, it's a weapon that can turn a match on its head.

Just ask Cameron Norrie. The British No. 1 tried his luck with an underarm serve during his round of 16 clash against Jannik Sinner at the Madrid Open. The result? A net-clipped disaster that ended in a straight-sets defeat (2-6, 5-7). It was a tough lesson in the fine line between genius and gaffe.

But here's the thing: when the underarm serve works, it's pure gold. Nick Kyrgios has turned it into an art form, never more memorably than during his 2019 Wimbledon showdown with Rafael Nadal. The Australian maverick, always one to play with flash and edge, caught the King of Clay completely off guard. It was a moment that had fans, pundits, and even Rafa himself shaking their heads in disbelief.

So what's the verdict on this divisive tactic? According to Andy Roddick, it's a no-brainer. The former world No. 1 and US Open champion has been a vocal advocate for the underarm serve, and he's not mincing words.

"It's a horrible play. It's literally only if you catch someone not paying attention. And at that point, if someone's not paying attention, guess what you do in sports? You expose it," Roddick said. "It's within the rules. I'm sorry, if I would pay someone to do this tactic all the time, I would literally have gone into every match and be like, I'll drop you $500 today if you just serve underhand."

The American legend didn't stop there. "We are the hardest sport in the world. And do you know when we look soft? When we complain about getting hit in doubles, and when we complain about someone hitting an underhand serve, as if they've done something to personally offend us. There is nothing wrong with it. If you get caught not paying attention, that's on you."

Roddick's point is spot-on. In a sport where players are constantly looking for any edge—from racket technology to fitness regimes—why should the underarm serve be off-limits? It's a legitimate tactic, one that requires perfect timing and a keen sense of your opponent's positioning. When it works, it's a thing of beauty. When it doesn't, well, it's just a bad day at the office.

For tennis fans and players alike, the underarm serve is here to stay. Whether you love it or hate it, it's a reminder that tennis isn't just about power and precision—it's also about outsmarting your opponent. And sometimes, the smartest play is the one they least expect.