411 REFERENCE · Wikibooks
Chess Opening Theory/1. d4/1...d5/2. c4/2...c6/3. Nf3/3...Nf6/4. Nc3/4...dxc4/5. a4/5...Bf5/6. Ne5/6...Nbd7/7. Nxc4/7...Qc7/8. g3/8...e5/9. dxe5/9...Nxe5
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Carlsbad variation D17 Carlsbad variation
9...Nxe5
The central pawns have been exchanged. White can, and should, play 10. Bf4, developing the bishop and pinning the knight on e5. This also justifies White's previous move 8. g3.
White's knight on c4 is hanging, so there isn't many alternatives. 10. Nxe5? doesn't develop any of White's pieces and allows Black to quickly catch up in development.
Theory table
10. Bf4 Nfd7 11. Bg2 g5 12. Ne4 gxf4 13. Nxf5 O-O-O 14. Qc2 10. ... ... 11. ... ... 12. Bxe5 Nxe5 13. Qd4 f6 14. O-O-O compensation 10. ... ... 11. ... f6 12. O-O Nc5 13. Ne3 Bg6 14. b4 +
References
See also