(L-R) Romania's Simona Halep, Serbia's Ana Ivanovic, Samantha Stosur of Australia, Anastasia Pavlyuchenkova of Russia, Alize Cornet of France, Bulgaria's Tsvetana Pironkova, Russia's Elena Vesnina and Maria Kirilenko pose during the draw ceremony for the Garanti Koza WTA Tournament of Champions in Sofia, Bulgaria, on Oct. 28, 2013. World's top tennis players will compete in the Garanti Koza WTA Tournament of Chanpions in Sofia on Oct. 29-Nov. 3. (Xinhua/Chen Hang)