opening - Why does 6.Bg5 prevent 6e5 in the Sicilian Najdorf

In Gufeld's book, after 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5!, [FEN ""] 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5! he writes: "In this way White solves three

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S. Bücker & C. Galofre - Chess Cafe - Over the Horizons - 1-74, PDF, Chess Openings

Should I play e6 or e5 in the Najdorf Sicilian? I heard that both are playable in most cases but there are some exceptions. - Quora

How to Play against the Najdorf Sicilian 6.Be2 Positional Approach - Chess Forums

S. Bücker & C. Galofre - Chess Cafe - Over the Horizons - 1-74, PDF, Chess Openings

Sicilian Najdorf 6.Bg5

Over The Horizons: Nimzowitsch and The Dutch Defense, PDF, Chess Openings

Should I play e6 or e5 in the Najdorf Sicilian? I heard that both are playable in most cases but there are some exceptions. - Quora

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