He’s not superstitious, but no hat means no worries for Holger Rune in Basel 

Something’s different about Holger Rune in Basel.

Rune had lost 10 of his last 11 matches, with a forced injury break in between, dating back to a quarterfinal showing at Wimbledon. But he's picked up three wins this week in Switzerland, and in two of them, the Dane ditched his trademark baseball cap.

While Rune's reason for doing so is rooted in pragmatism, freeing his golden locks could be just the thing that sends him to the ATP Finals. He started the week with a 1-6, 7-5, 6-3 comeback against Serbia's Miomir Kecmanovic, and made the choice to change things up halfway through his 7-6(2), 6-1 win over Argentine Sebastian Baez in the second round.

“It’s extremely hot in this arena,” he said after beating Baez. “After the first set, I was sweating a lot and I had to control [the hat] all the time, so [I thought] let’s play without it and see what happens.”

Rune returned the court hat-free on Friday, when he gutted out a three-set quarterfinal match against another Argentine, Tomas Martin Etcheverry. He came out of the gate swinging, wasting no time getting a 6-1, one-set lead.

The level of tennis was simply on point for Rune in the first 34 minutes, but when the match clock struck 35, the tide turned. He lost serve for the first time in the fourth game of the second set, and eventually needed three match points in a thrilling final-set tiebreak to book a spot in the semifinals.

Might Rune make the change permanent? It's too early to tell. But for as much as new coach Boris Becker may be influencing Rune’s end-of-year run, playing without his signature accessory might be the secret to securing the Dane a Turin debut. He currently sits just over 200 points ahead of American Taylor Fritz for the eighth and final year-end berth.

“It’s not that I’m superstitious, but I mean it’s working pretty well,” Rune said. “It’s good to get some air to the hair as well if you want to have some hair when you’re 50, so I’m enjoying myself.”