What is the fine-grained topic of the following text: By the way, directly after these recordings were made Wesley So played the London Chess Classic 2017 where he defeated ex-world champion Vishy Anand as black, employing the topical …a5 (instead of …a6) which of course is also treated on this DVD. Only return the topic.
Wesley So's performance at the London Chess Classic 2017 and his use of a specific chess move.