Thirty-nine year old Ivo Karlovic, who faces German Jan-Lennard Struff in the Wimbledon second round on Wednesday, has accomplished much to be proud of during his 19-year career. He’s won eight tour-level titles, including five since he entered his mid-30s. He’s hit more than 12,700 aces and has earned more than $9 million in prize money.

Earlier this year, he became the oldest player to reach the Australian Open third round in 40 years, since 44-year-old Ken Rosewall in 1978.

But Karlovic, like most working folks, would still handle a thing or two differently if he could do over his career. Namely, he’d change his one-handed backhand. The 6’11” right-hander holds 92 per cent of the time, but, like other big servers, he struggles to break, winning only nine per cent of his return games, according to his Infosys ATP Scores & Stats.

But a better backhand, Karlovic thinks, more specifically, a two-handed backhand would have helped him break more often throughout his career.

“The No. 1 thing that I always regret is not having a two-handed backhand. Because I think in today’s game it would be a lot easier to return the ball,” Karlovic told ATPWorldTour.com. “Plus, I don’t know anybody who is tall and has a one-handed backhand, because it’s really difficult. When I was young, if I had a different coach, probably I would be even better.”

Few coaches, at the time, though, were teaching two-handed backhands, and the ATP World Tour stars Karlovic watched on TV while growing up in Croatia in the 1980s and ’90s – John McEnroe, Boris Becker and Stefan Edberg – all had one-handed backhands.

Watch: Ace King Karlovic Continues To Thrive

But at least tennis didn’t lose the well-liked and easy-going Dr. Ivo because of frustration. That’s more that can be said for basketball.

Karlovic tried out the sport when he was 13. The Croatian was barely a teenager but he was already 6’6” and, because of tennis, could cut well and run the floor. So coaches made him practise with 18- and 19-year-olds. That didn’t go well with Karlovic. He quit after six months and never went back, despite five years of calls from the basketball coaches.

“They were on the phone every day, calling me to come back, years after that, every day. Unbelievable. But I was always saying no,” Karlovic said. “The last time they called me was when I was 18.”

The big man, however, has no immediate plans of stopping tennis. So long as he’s healthy and able to play the big tournaments, such as Wimbledon, he’ll be on court.

“It’s all about injuries, health and motivation,” Karlovic said. “Right now I’m healthy and motivated, so as long as my [ATP] Ranking is up where I can be at all the events, I will not think about retiring.”

The fashion news out of the way, the focus will surely be all on tennis on Wednesday when Roger Federer faces Lukas Lacko of Slovakia for a place in the third round at Wimbledon (second on Centre Court). Federer surprised fans and industry observers on day one when he walked onto Centre Court with no Nike swoosh in sight, instead wearing the all-white clothes from Uniqlo, his new clothing sponsor.

“I was excited to wear Uniqlo today. I must tell you, it’s been a long time coming. I felt very good out there. It’s also crucial to play well, so it was helpful,” Federer said.

The Swiss star had been with Nike for 20 years, as long as he’s played at Wimbledon. The 36-year-old became the first man in the Open Era to make 20 consecutive Wimbledon appearances. Federer also evened Jimmy Connors’ Open Era record for most total appearances at the All England Club.

Lukas Lacko, who made his second ATP World Tour final last week in Eastbourne (l. to M. Zverev), took advantage of a nice draw to start The Championships, beating French qualifier Benjamin Bonzi in four sets. He’ll face bigger odds against Federer: The Swiss has lost in the Wimbledon second round only once, in 2013 to Ukraine’s Sergiy Stakhovsky.

Marin Cilic, the man Federer beat in last year’s final, will look to win his seventh match in a row against Argentine Guido Pella (third on No. 1 Court). Cilic beat Novak Djokovic in the Fever-Tree Championships final last month to capture his 18^th tour-level title and second on grass.

Canada’s Milos Raonic, 2016 Wimbledon finalist, struck 18 aces in his first-round win against Brit Liam Broady. The 13^th seed will hope for a repeat effort against Aussie John Millman, who’s trying to reach the third round of a Grand Slam for the fourth time and second at Wimbledon (2016, l. to Murray).

Eighth seed Kevin Anderson, three times a Round of 16 finisher at SW19, meets Italy’s Andreas Seppi, and Stakhovsky will have another chance at a Wimbledon upset when he meets 11^th seed Sam Querrey, a semi-finalist last year.

In a battle of #NextGenATP old and new, American Jared Donaldson will meet 31^st seed Stefanos Tsitsipas of Greece. Donaldson competed at the 2017 Next Gen ATP Finals, but he was born before 1997, making him ineligible for this year’s Next Gen ATP Finals, to be held 6-10 November in Milan.

Tsitsipas, however, is only 19 and is in good position to make his debut at the 21-and-under event. The Greek right-hander is currently in third place in the ATP Race To Milan, which will determine seven of the eight players who compete at the prestigious event. The eighth spot will be rewarded to the winner of an all-Italian qualifying tournament held just before the Next Gen ATP Finals.

Just seven different men have captured the Wimbledon title in the Open Era without competing at a grass-court event beforehand. Juan Martin del Potro, attempting to become No. 8 on that list, got off to a strong start on Tuesday.

The Argentine fifth seed faced few complications in dispatching tricky German Peter Gojowczyk 6-3, 6-4, 6-3 in one hour, 50 minutes to advance to the second round.

While the 29-year-old is playing his first event on the surface in 2018, he arrives at the third major of the year in good form, having advanced to the Roland Garros semi-finals for the first time since 2009. The World No. 4 will also still be carrying the confidence from capturing his maiden ATP World Tour Masters 1000 trophy at the BNP Paribas Open in March.

Del Potro, who has now won at least one match in each of his nine appearances in this tournament, hit 22 aces and broke three times without getting broken himself to defeat the World No. 39. He earns his 18th match win at Wimbledon, putting him just one behind David Nalbandian (19) for the most victories on the historic grass by an Argentine. Del Potro, now holding 85 Grand Slam wins, is also just one triumph behind Nalbandian for second in their country’s history.

A stiff test awaits in the second round, though. Del Potro next faces 2017 Fever-Tree Championships titlist Feliciano Lopez, who beat Argentine Federico Delbonis 6-3, 6-4, 6-2. By competing, the Spaniard breaks Roger Federer’s all-time record by playing in his 66th straight Grand Slam main draw. Lopez has not missed a major since the 2002 Australian Open.

“When I was about to break the record, I thought, ‘Wow, I’m going to beat Federer at something’, which is a lot already,” Lopez said with a laugh. “It”s only a number, and I’m really proud of my consistency. It’s not about the number of Grand Slams played. It’s about how many years I have been playing at the top level. This is the most important thing.”

Lopez and Federer have known one another since they played the Under-16 division of the Junior European Championships two decades ago. And the Swiss said after his own victory on Monday that he is happy for Lopez.

“It’s nice that more and more players are able to keep themselves in shape,” Federer said. “That we can talk about breaking each other’s records, him breaking mine, it’s a great thing. It’s a testament for both of us to keep ourselves in shape, loving the sport. I hope that many more players can achieve such a thing.”

Did You Know?
Del Potro has captured 22 tour-level titles, but none of them have come on grass. Michael Stich, Andre Agassi and Novak Djokovic are the only three men in the Open Era to have won their first grass court titles at Wimbledon, in 1991, 1992 and 2011, respectively.