What is the name of this variation:
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1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 Nbd7
It's an old main line of Sicilian Najdorf, and according to Wikipedia, it's the De Verbeterde List, or Improved Strategem, due to recent efforts by Dutch players to revive it.
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6
is the Najdorf variation. I don't know if6.Bg5 Nbd7
has a name of its own.