Even if Vika loses first round, Maria has to make semis
Serena will stay #1 regardless
she did win Rome and Madrid
Vika has to lose R1, R2 or R3 and Maria has to make semis to stay #2
If Vika loses in R4 or QF, Maria has to make the finals.
If Vika loses in Semis, Maria has to win.
If Vika makes the final, she will be #2.