Black is ready to castle by hand.
1. d2d4  1... g8f6  2. g1f3  2... d7d5  3. c1f4  3... c8f5  4. e2e3  4... e7e6  5. c2c4  5... f5b1 Quite a tricky line  which So used with both colors. 6. d1b1  6... f8b4  7. e1d1  7... b4d6  8. f4g5  8... h7h6  9. g5f6  9... d8f6  10. c4d5  10... e6d5  11. e3e4  11... d6e7  12. f1b5 