After 3.Bg5 (see diagram), Black's most popular choices are 3...Nbd7, 3...e6, 3...Bf5, 3...c6, and 3...c5, all potentially leading to different variations.
* 3...h7-h6* 3...Kf6-e4* 3...g7-g6* 3...c7-c5* 3...c7-c6* 3...Cc8-f5* 3...Kb8-d7* Карпов А.Е., Kалиниченко Н.М.