It is sometimes said of the rivalry between Roger Federer and Rafael Nadal down the years that it should not actually be called a rivalry unless both sides win with about the same regularity. If one player is beating the other one more often than not, then does it really count?

That might sound harsh toward Federer, who has won 10 of his 28 matches with Nadal and three of their past five. But there was a spell, between 2008 and the latter stages of 2011, when Nadal was utterly dominant, winning nine of their 11 matches, and not just on clay. Federer has actually won two of the past three, but Nadal has won eight of their 10 grand slam meetings, including each of the past five.

You can make good arguments either way on this matter but it struck me, watching the end of the Victoria Azarenka-Maria Sharapova final in Beijing on Sunday that something similar is happening in the women’s game at the moment. Now no one is suggesting that the Aza-Shazza rivalry is anything to compare with the “Fedal” contests but the world’s top two have met five times in 2012, four of them in finals, with Azarenka winning three of them.

Sharapova’s only win was on clay in Stuttgart, just before her fabulous victory at the French Open, while Azarenka won their only grand slam meeting this year, at the Australian Open where she clinched her first grand slam title. Overall, Azarenka leads 7-4 but in winning four of their past five, the Belarussian has shown she has more than the upper hand. Indeed, since she became really good (since 2010), Azarenka has won six of the past eight.

It is no secret that there is no love lost between the two, which helps the rivalry, to a certain extent, but Azarenka has won in straight sets in three of her past four wins against Sharapova, who has played below par, to say the least, in most of them. For some reason, the Russian, who could well finish 2012 with her best ever win-loss record, struggles to produce against the current world No 1.

There is little to choose between the power of the two and though Azarenka’s relatively weak serve (her technique can let her down, especially on second serve) can be got at, she tends to make up for it with better movement than Sharapova can muster. By contrast, when Sharapova has a bad day on serve, it tends to result in double faults.

Unforced errors have let her down, too, but Sharapova will forever be a player who goes for everything so when she’s off her game, which is rare, she will rack up big numbers. She wants to dictate and Azarenka is good enough not to let her.

Though Serena Williams remains the best player when she’s 100 percent fit and healthy, the world’s top two are building some sort of rivalry, which could be reignited in Istanbul in a couple of weeks’ time. For rivalry’s sake, though, it would probably be good if Sharapova could win the next one.