A hidden dynamic of clay court versus hard court tennis is perfectly illustrated with points won behind second serves. You would naturally think that serving on a hard court would be preferred for both first and second serves, but it’s simply not the case.

An Infosys ATP Beyond The Numbers analysis of points won behind first and second serves on both hard and clay courts last season surprisingly reveals a higher win percentage behind second serves on clay.

The data set includes the leading 20 players in the First and Second Serve Points Won categories on both clay and hard in the 2017 season.

2017 First Serves: Leading 20 Players Average Points Won

It’s clear to see that first-serve performance was superior on hard over clay, but that flips when we examine second serves.

2017 Second Serves: Leading 20 Players Average Points Won

An analysis of World No. 1, Rafael Nadal confirms the advantage clay has over hard when the point starts with a second serve. In 2017, Nadal led the ATP World Tour in winning second serve points on both hard and clay courts, with his performance on clay being superior to hard.

2017: Nadal Second Serve Points Won

This dynamic was also true for one of the biggest servers on the ATP World Tour; John Isner. The 6’10” American won 56.1 per cent (510/909) of second-serve points on hard courts, but that rose to 58.3 per cent (187/321) on clay. Isner was the only other player besides Nadal that featured in the Top 10 in winning second-serve points on both clay and hard.

One reason to explain this dynamic is that raw power is sought after behind first serves, and the ball slows down less at impact on a hard court than a clay court. But power is not the main ingredient of second serves. The focus switches to what the ball does when it reacts with the court, with the granules of clay “grabbing” a ball better and producing a higher kick off clay than hard.

It turns out that a heavy kick second serve is rewarded more on clay than we ever thought.

Ten months ago, Kei Nishikori couldn’t have imagined he’d be where he is today. The Japanese right-hander started his year in late January in Newport Beach at an ATP Challenger Tour event. And he lost, to No. 238 Dennis Novikov of the U.S., 6-3, 3-6, 6-4.

But now, Nishikori, who beat #NextGenATP American Frances Tiafoe on Tuesday to start his Erste Bank Open 500 in Vienna, could end his season among the top eight players in the world at the Nitto ATP Finals.

“It wasn’t easy to imagine but now, the last couple of months especially, I’ve been playing really well and have a lot of confidence. I’m happy to be back at this level,” Nishikori told ATPWorldTour.com.

The 28-year-old is currently in 10^th position in the ATP Race To London, with just three spots remaining at the season-ending tournament, to be held 11-18 November at The O2 in London.

Nishikori has 3,000 Race points, 65 behind ninth-placed John Isner (3,065), who, at age 33, is trying to make his London debut. Isner also advanced on Tuesday in Vienna, saving two match points to beat Brit Cameron Norrie.

For Nishikori, it has been a relatively quick climb back to the top of the ATP World Tour. He underwent surgery on his right wrist last August and missed the final three months of the season.

In the off-season, he tweaked his service motion so it relied less on his wrist. “I had to try to not use it too much… We discussed it with my coaches, and we changed some things. It’s a better movement, a better swing and I think it’s going well,” he said.

But after his opening loss in Newport Beach, Nishikori won five consecutive matches to take the title at The RBC Tennis Championships of Dallas, also an ATP Challenger Tour event. Two weeks later, he was back in the hunt for ATP World Tour titles, making the semi-finals at the New York Open (l. to eventual titlist Anderson).

By late April, Nishikori was competing for some of the biggest titles in the game. He fell to Rafael Nadal in the Rolex Monte-Carlo Masters final.

Watch Highlights: Nishikori Beats Tiafoe In Vienna

Nishikori has played some of his best tennis in the biggest tournaments this year. He made the Rome quarter-finals, his first Wimbledon quarter-final and the semi-finals at the US Open.

“I think I was going slowly at first. I was really struggling to play, and I didn’t feel the rhythm… I didn’t have any confidence so it took a little while to come back to 100 per cent… Now I think I’m back,” Nishikori said.

This week is his first at the ATP World Tour 500-level event in Vienna. But so far, on and off the court, Nishikori has enjoyed his time in the Austrian city. On Monday, he, along with Kevin Anderson, Lucas Pouille and Philipp Kohlschreiber, visited the Vienna State Opera.

“It was beautiful, one of the best experiences I’ve had in my life. I’ve never seen an opera house before,” Nishikori said.

His mother is a piano teacher, but Nishikori confirmed, the family’s musical talents have not yet extended to singing, although a member of Nishikori’s coaching staff is apparently an excellent singer.

“We don’t sing too much. I think coach Michael [Chang] is very good at singing. I’ve heard before. He’s very good,” Nishikori joked. “I always wanted to come here to visit, and it’s fun to play different tournaments. I’ve heard Vienna is a great city. I’ve seen many great buildings and many beautiful things here in the city. I’ve been liking it.”

Roger Federer had to shake off some rust, but the eight-time champion eventually rediscovered his “Basel” gear and leaned on the home crowd to advance 6-2, 4-6, 6-4 on Tuesday against Serbian Filip Krajinovic.

The 37-year-old Swiss won his 16^th consecutive match at the Swiss Indoors Basel, since losing the 2013 final to Juan Martin del Potro. Federer is trying to reach his 14^th hometown final and capture career title No. 99.

“It was a bit more of a hard-fought victory, but they feel good too, especially knowing that I have the day off tomorrow, so it’s no problem having played three sets today,” Federer said. 

The World No. 3 wasn’t his usual self throughout the match, and especially at the start. Federer shanked forehands and missed whenever he stepped into the court in the beginning. The top seed faced two break points, at 15/40, 1-2, but saved both and broke immediately after, slapping a second-serve return for the first break of the match.

From 1-2 down, Federer won the next seven games against the 2017 Rolex Paris Masters finalist. But Krajinovic relaxed in the second and broke Federer, who struggled to find his forehand all match (23 unforced errors), in the eighth and 10th games to take the second.

Behind the red-and-white clad home crowd, however, Federer upped his first-serve percentage and advanced, despite being broken while first serving for the match at 5-3. The Swiss landed only 47 per cent of his first offerings overall.

“I didn’t serve very well today. I think I was misfiring the corners, I was not hitting the lines enough. Clearly you make your life more difficult, but still I was up 6-2, 3-1, break points, so things could have ended very quickly today, even though I didn’t have the best serve percentage stats. But maybe that’s exactly what caught up to me eventually,” Federer said.

“It’s just getting used to it. This is where the first rounds can be tricky.”

He will next meet German Jan-Lennard Struff, who beat Aussie John Millman 7-6(3), 6-2. Federer has won all three of their FedEx ATP Head2Head meetings, including two earlier this year at the Australian Open and Wimbledon.

Elsewhere, seventh-seeded Russian Daniil Medvedev, who is currently at a career-high No. 20 in the ATP Rankings, knocked out Maximilian Marterer of Germany 6-3, 7-5 in 85 minutes. It was Medvedev’s 40th match win of the year (35-13 on hard courts), which includes three ATP World Tour titles at the Sydney International (d. De Minaur), the Winston-Salem Open (d. Johnson) and the Rakuten Japan Open Tennis Championships 2018 (d. Nishikori).

In other action, qualifier Alexei Popyrin recorded his first ATP World Tour match win over fellow Australian Matthew Ebden 7-6(4), 6-4 in one hour and 33 minutes, while Italian Andreas Seppi knocked out qualifier Taro Daniel of Japan 6-0, 6-4 in 63 minutes.