Women’s tennis is hardly ever discussed today without a mention of Jelena Jankovic and Ana Ivanovic, who are currently world No.1 and No.5 respectively. The two Serbians may not dominate the WTA Tour, but they have secured a niche among the elite of the game.

Originally from the non-tennis city of Belgrade, these two girls have climbed the rankings because of their hunger and will to win. They remind me a great deal of the rivalry between the two Belgians girls, Justine Henin and Kim Clijsters.

Jankovic agrees, and said recently: “One of us will reach No.1 soon, and then it will be depending on who is on form for the rest of the year. We push each other and we motivate each other to be better players. It's great for Serbian tennis and the world to have new faces, to have new players and great rivalries."

Indeed, they have both achieved the coveted No.1 spot; first it was Ivanovic in June 2008, and Jankovic took over later in August. However, neither of the two Monica Seles admirers could handle the pressure of being at the top.

Their performance consistency wasn’t high enough to keep them at the top for very long. They both had to cope with injuries, but they weren’t the only reason they were both toppled.

Lack of focus and determination came into play. As a personal observation, Ivanovic and Jankovic both played better tennis when they were in the No.2 spot. This was probably because they became more focused and determined, and they had more purpose to up their game.

And this endorses my view that players perform better when they are catching up from behind than when they are actually in the top spot.

Jankovic and Ivanovic are the best and most skilled and powerful baseline players on tour today. They can trounce any of the top 10 players (Williamses included) and currently deserve their respective rankings. But the interesting question is, who is the more enduring player?

Their head-to-heads are 7-1 in favour of the younger Ivanovic, but Jankovic leads in the title stakes 8-7. However, the telling figures are their respective win-loss ratios. Jankovic has a winning average of 48% (324-168) while Ivanovic has a 66% winning ratio (207-71).

I am more inclined to the view that Ivanovic is more consistent than Jankovic in terms of overall perforamance (historical records also taken into account), but this judgement could very well be wide of the mark if Jankovic can learn from her previous mistakes and improve her focus now that she is back in top spot. Maybe she will, or again she could thaw under the pressure.

Champions are not defined by how quickly they rise from the ranks or how young they are when they earn their titles. It is rather by their ability to uphold their level of performance and their ability to meet expectation. Exceeding their own expectations is what they do best. They play to win! They have the mental edge to win matches even if circumstances are totally against them.

Ivanovic and Jankovic still have long careers ahead of them, but it would not hurt either of them to look back at previous champions who, in their own ways, dominated the women’s scene at a level of consistency few could have imagined.