The alternative is 10...h6 and it seems as it pushes to become the main line.
1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... a7a6  4. b5a4  4... g8f6  5. d2d3  5... d7d6  6. c2c3  6... g7g6  7. e1g1  7... f8g7  8. f1e1  8... e8g8  9. b1d2  9... f8e8  10. d2f1 