Serena battling to keep #1 ranking

With Jelena Jankovic winning the China Open, she comes within 21 points of Serena's number one ranking. With the number one ranking pretty much on the line, here's a scenario of how things could play out for Serena and Jelena. If one of the two loses second round and the other goes further, the one who goes further will be No.1; if they both lose in the second round, Jankovic will be No.1. If Williams wins her second round match, Jankovic's chances of becoming No.1 diminish significantly - Jankovic would have to do two wins better than Williams, so she would have to be either runner-up (with Williams losing in the quarters) or champion (with Williams losing in the semis). If Williams reaches the final, No.1 is safe, win or lose.