No. 109, Apr. 1994 - SOLUTIONS

3098 - V. Sokolow

The wQ can only be legally added on a1, b1 or c1.

a) +wQc1 and play 1. d3!
b) +wQb1 and play 1. c3!
c) +wQa1 and play 1. b3!

3099 - Thomas Volet

The position unlocks by the retraction of -1. Kc7-c8 a4-a3 -2. Rc8-b8 Rb8-a8 -3. e6xPf7 Ra8-b8 -4. d5xNe6 Nf4-e6+ -5. c4xQd5 Qd3-d5 -6. Rb8-c8 Qc3-d3 -7. Kc8-c7 Ne6-f4 -8. Bc7-d8 Nd8-e6+ -9. Be5-c7 Qa5-c3 -10. Kc7-c8 Qa6-a5 -11. Rc8-b8 Rb8-a8 -12. Bb2-e5 Ka8-a7 -13. Bc1-b2 Qa7-a6 -14. b2-b3 Bb3-a2 -15. Ra6-b6 Ba2-b3 -16. Ra5-a6 Bb3-a2 -17. Ba2-b1 Qa6-a7 -18. Bb1-a2 Ka7-a8 -19. Ba2-b1 Ra8-b8 -20. Bb1-a2 Ba2-b3 -21. Rb8-c8 Bb3-a2 -22. Kc8-c7 Kb6-a7 -23. Ba2-b1. There are a few duals but it is not possible to let White have the move.

Black has the move and mates in 2 with 1 ... Rxb8+.

3100 - N. Plaksin and A. Zolotarev

Retract -1. Ba6xQb5# Qh5-b5+ -2. Rb5-b6+ Bg7-f6 -3. f6xQe7 Qe2-h5 -4. f5-f6 Qe1-e2 -5. f4-f5 e2-e1=Q -6. f3-f4 d3xRe2 -7. Re1-e2 and White avoids retro-stalemate.

Then the position unlocks by retracting the following maneuvers: Qe7 issued from h3-h2-h1=Q, then retract wPh2xQg3 and unpromote this Q through bPa5xBb4-...-b2-b1=Q. Meanwhile unpromote bBg1 through g3-g2-g1=B, uncapture wPg2xQf3, and unpromote this Q through b3-b2-b1=Q. Then drive wBb4 to c1 and retract b2xQc3. Everything unlocks.

Four Ceriani-Frolkin Q-promotions!