La Genesi delle Posizioni, 1961
11+13. Release the position
Analysis: 2 wh. captures are -1. Bb8xc7+ and one by wPe7. So that at least one of wPb6 and wPc6 did not leave its column, requiring at least 3 bl. caps by bPs a7, b7 & c7. Thus (1) bPh4 is from h7 with no capture, (2) 3rd wh. cap is gxh, (3) both wPs b6 and c6 did not capture and (4) all five bl. caps are identified: axb, fxg, cross-captures bxc & cxb, and wPh on its column. We now see that wPe7 is from d2. Necessarily wPa2 and wPf2 promoted on a8 and f8=B for balance. We cannot retract bl. axb for now.
The position unlocks when we unpromote wNa6 (no other possibility) on a8 and retract this P up to a5, allowing the retraction of bPa6xb5. We need tempo-moves to bypass the retro-opposition. Just bPh5-h4 is not enough: we also need to uncapture wPh3 so that wPh2-h3 will be one more tempo. Thus -1. Bb8xRc7+ because a bN cannot reach h3 while a bR can.
Retract -1. Bb8xRc7 Nc8-a7 -2. Ba7-c8 Rb7-c7 -3. Nc7-a6?? and we cannot extract the bR. It would have been possible to extract it by changing side to move, which is possible using a tricky ortho-reconstruction maneuver:
-3. Nb8-a6!! Rc7-b7 -4. Nd7-b8 Rb7-c7 -5. Nf8-d7 Qg8-f7 -6. Ke8-d8 Rd7-b7 -7. Kd8-e8 Rc7-d7+ -8. Nd7-f8 Qf7-g8+ -9. Nb8-d7 Rb7-c7 -10. Na6-b8 and now bl. is to move.
We go on -10 ... Rb8-b7 -11. Nc7-a6 Ra8-b8 -12. Bb8-a7 Ra3-a8 -13. Ba7-b8 Rh3-a3 -14. Bb8-a7 Ra3xPh3 -15. Ba7-b8 Ra1-a3 -16. Bb8-a7 Ra8-a1 -17. Ba7-b8 Rb8-a8 -18. Na6-c7 Rb7-b8
Now we need to switch side again, using the same maneuver: -19 ... -26. Na6-b8 Rb8-b7 -27. Nc7-a6 Rb7-b8 -28. Na8-c7 Rc7-b7 -29. Bb8-a7 Na7-c8 -30. h2-h3 Nc8-a7 -31. a7-a8=N h5-h4 -32. a6-a7 Na7-c8 -33. a5-a6 a6xb5 and everything unlocks.