In the spirit of the Najdorf Sicilian $1 This move will either slow down the opponent considerable, or will add rocket fuel to his attack. It was a also a novelty, played after serious thought.
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. e2e3  4... e8g8  5. f1d3  5... d7d5  6. c4d5  6... e6d5  7. a2a3  7... b4d6  8. d1c2  8... c7c6 Instead both players are entering the Carlsbad pawn structure, with a white dark-squared bishop behind the pawn chain. 9. g1e2 Without the bishop, this seems the most sensible plan for So. He is preparing a kingside attack as soon as he can. 9... f8e8  10. c1d2  10... b8d7  11. f2f3 Botvinnik's plan, which is best met with 11... c6c5 Now the e3-e4 break is out of the question, but White can go for 12. h2h4 Or the immediate 12.0-0-0 which is a critical line as well.