Is the Poisoned Pawn variation of the Najdorf (7... Qb6) considered some sort of refutation of 6.Bg5? As title above, is the Poisoned Pawn variation of the Najdorf considered some sort of refutation of 6.Bg5, and the reason why 6.Bg5 is rarely seen at top level these days?
The problem with Bg5 is mainly that black will usually be better prepared than white in the messy poisoned pawn. He either doesn't play it or he knows it. On the other hand imagine Be3. There black is quite predictable as not following the main lines is too dangerous. White has a lot of good systems to try so he has much easier life. Objective quality is not that important part of decision process what to play as Be3 Najdorf, Bg5 Najdorf as well as Queen's Indian end virtually always in draw in correspondence games. To me Be3 Najdorf seems so unpractical for black that I would prefer dragon, Sveshnikov or classical over it. Knowing that with white, who would try so hardly to get the Bg5 mess against well prepared opponent?