Whoever first observed that tennis isn’t “rocket science” had it right. It’s only racket science, a slightly less daunting discipline, but one that has its own special challenges, rewards and revelations. So let’s delve right into some of the more striking numbers and details recently generated by the sport.

Maybe it is all in Ivo’s head: Statistics in tennis tend to underscore how critical the “mental game” is to success. Take the “first-serve points won” numbers. The difference between 2015 tour leader Ivo Karlovic and second-place Milos Raonic is just two percentage points. (Karlovic was successful 85 percent of the time in 17 matches; Raonic won 83 percent in 14 matches.)

Roger Federer is No. 3 on that list with 81 percent in 12 matches. Three men, Sam Querrey, Tomas Berdych and Gilles Muller are all one measly percentage point behind Federer. The statistical margins in tennis tend to be very slim, as many as five or six players are often deadlocked with identical numbers.

Thus, Karlovic’s utter dominance in the “break points saved” category is striking. Going into Indian Wells (where the big fella lost to Steve Johnson), Karlovic had successfully fended off 90 percent of the break points he faced (57 of 63 in 17 matches). The next man on the list is Federer, who’s at 77 percent (33 of 43 in 12 matches). That’s an enormous gap that can’t simply be explained away by the fact that Ivo has a monster serve. Mullers does, too. And if Federer doesn’t, he’s certainly the craftiest server out there.

Karlovic got off to a great start this year, and this statistic helps explain why. He has served his best when he’s needed it most. And that’s not something everyone can do.

The Kournikova Factor: Anna Kournikova, the most frequently searched “term” on the Internet at one point back around the turn of the century, took a lot of criticism for never having won a WTA tournament. People simply forgot -- or preferred to ignore -- the fact that she was a Wimbledon singles semifinalist (1997) who was ranked as high as No. 8 in singles (2000) and No. 1 in doubles. If you had to choose, would you take the career of, oh, Karin Knapp (she won Tashkent last year) over Kournikova’s?

Anyway, the data miners over at the Tennis Abstract have searched out the best players who have yet to win a WTA event. The top five, starting with the highest ranked: No. 19 Shuai Peng of China, No. 30 Varvara Lepchenko, No. 32 Zarina Diyas, No. 33 Camila Giorgi and No. 35 Casey Dellacqua.

One name jumps out of that list of frustrated contenders -- No. 42 Sloane Stephens. She will have to wait longer after losing to Serena Williams in three sets at Indian Wells.

He actually does bleed red: Switzerland’s failure to defend the Davis Cup in a first-round tie with lowly Belgium a few weeks ago was a non-story. But we ought to acknowledge that the Swiss B-team, which is also the nation's C, D, E and F team, acquitted themselves honorably, forcing the host team to a fifth-and-decisive rubber to secure the 3-2 win.

Some complained about Federer's and Stan Wawrinka’s apparent lack of tennis patriotism when they chose to skip the tie. While it certainly looked like the two stars had secured the trophy for the Swiss for the first time merely so they could check off the accomplishment on a career bucket list, the reality is both men have given much to the Davis Cup through the years. Federer is 50-17 overall, 38-8 in singles. Wawrinka is 25-25, 21-13 in singles.

So let’s compare the numbers of some recently retired stars to see how they match up. Boris Becker of Germany was 54-12 (38-3 in singles), Andre Agassi was 30-6 (all in singles), Pete Sampras went 19-9 (15-8), while Andy Roddick was 33-12 (all in singles). Bjorn Borg was 45-11 (35-3). Among active players, most of whom are at least four years younger than Federer, Rafael Nadal is 24-5 (21-1), Novak Djokovic is 30-9 (27-7) and Andy Murray is 25-7 (21-2).

It doesn’t look like Federer owes Switzerland anything, does it?