[%c_effect a3;square;a3;type;GreatFind;persistent;true] Avoiding 14...Nb4.
1. e2e4  1... e7e5  2. g1f3  2... g8f6  3. f3e5  3... d7d6  4. e5f3  4... f6e4  5. d2d4  5... d6d5  6. f1d3  6... f8d6 This variation of the Petroff Defense is very popular nowadays. Nepomniachtchi had great success with it in last year's Candidates Tournament. 7. e1g1  7... e8g8  8. c2c4  8... c7c6  9. f1e1  9... c8f5  10. d1b3  10... d8d7  11. c1e3  11... d5c4  12. d3c4  12... b7b5 A new and good move. It guarantees the a6-square for the knight. 13. c4d3  13... b8a6 