Stat attack: Day 10 preview

2 - The number of times Roger Federer’s serve has been broken at Roland-Garros this year out of a total of 56 games as he prepares to tackle his old friend Stan Wawrinka on Court Suzanne-Lenglen.

4 - Petra Martic has played a quartet of matches with Czech teenager Marketa Vondrousova over the past two years and won them all, a good omen for the experienced Croat before their clash on Court Suzanne-Lenglen.

5 - The amount of sets that Johanna Konta and Sloane Stephens have contested this year in two tussles which were both won by the Briton. Stephens has taken just one of those sets, in Rome last month, and will be looking to gain revenge on Court Philippe-Chatrier.

12 - The number of successive sets that Federer has won here this year. He is one of four quarter-finalists along with Novak Djokovic, Vondrousova and Amanda Anisimova who have yet to drop a set here.

21 - The number of games that Vondrousova has lost at Roland-Garros this year - fewer than any other quarter-finalist.

26 - When Federer and Wawrinka meet, it will be the 26th time the Swiss friends have played, making it the fourth most contested rivalry between men players with one-handed backhands in the Open era. They still have some way to go to equal the 36 times that Ivan Lendl and John McEnroe tussled - and those two weren't exactly buddies like Roger and Stan!

35 - The number of days since Sloane Stephens, who meets Johanna Konta on Court Philippe-Chatrier, announced her engagement to US soccer star Jozy Altidore.

56 - The number of aces served by Wawrinka, the second most by any man left in the tournament behind Alexander Zverev's 61.

64 - The percentage of points won on his second serve by Rafael Nadal, the highest of any player, man or woman, left in the tournament as he prepares to play Kei Nishikori on Court Philippe-Chatrier.

69  - The percentage of successful first serves delivered by Federer through the tournament, the highest of any man left in the singles. Federer, third on the Infosys Slam Leaderboard, heads the first-serve statistical category among the men.

70 - The first-serve percentage of Sloane Stephens throughout the season, the second highest of any woman on tour in 2019 behind Madison Brengle.

73 - The percentage of points won on first serve by Vondrousova (95 out of 131), the best by any player left in the quarter-finals.

219 - Johanna Konta’s Infosys Slam Leaderboard points, making her the top-rated woman player going into the quarter-finals.

270 - Rafael Nadal’s total number of points on the Infosys Slam Leaderboard, making him the tournament’s top-rated male player here after four rounds.