[Retros] Switchbacks in PGs

[Paul R]

Hi,

N. Dupont said :


>In fact, an entirely subsection must be devoted to switchbacks. For

>example, I perhaps own the one by a single promoted piece (8.5 GD50), the

>record for a single piece is higher, the absolute record too, but I don't

>remember the games...


The record of ten switchbacks is P1000601:
Unto Heinonen
R069 Probleemblad  09/1999
1.g4 c5 2. g5 Sc6 3. g6 Tb8 4. gxh7 g5 5. Sf3 Lh6
6. Tg1 Kf8 7. Tg4 De8 8. Tc4 g4 9. e4 g3 10. e5 g2 11. e6 g1=T 12. exd7
Tg3 13. d8=D Lh3 14. b4 Lxf1 15. b5 Lh3 16. b6 Lc8 17. bxa7 e6 18. a8=D
Sge7 19. Da4 Thg8 20. h8=L Ta8 21. Ld4 Th8 22. Sa3 Sg8 23. Df6 Dd8 24.
Tb1 Ke8 25. Tb5 Lf8 26. Ta5 b5 27. Sg1 b4 28. Ddf3 b3 29. Db4 b2 30.
Dfb3 b1=T 31. f3 Ta1 32. Sb1 Sb8
10 Switchbacks (alle 8 schwarzen Steine, 7 davon ohne Schlag; wSg1, wSb1)
The record of six switchbacks without captures is P1068530:
Satoshi Hashimoto
Probleemblad  06/2005
1.g4 d5 2. Lg2 d4 3. Lc6+ Sd7 4. Lb5 c6 5. f3 Da5
6. Kf2 Sb6 7. Kg3 Kd7 8. Kh4 g5+ 9. Kh5 Lg7 10. Sa3 Le5 11. Sc4 Sf6+
12. Kh6 Ke6 13. Kg7 Sg8+ 14. Kf8 Lg7+ 15. Ke8 Lf8 16. Kd8 Ld7+ 17. Kc7
Td8 18. a3 Lc8 19. Kb8 Kd7 20. Se5+ Ke8 21. c4 Td6 22. Da4 Sd7+ 23. Ka8
Dd8 24. Da5 Sb8
These examples can be found in Switchbacks dans les parties justificatives - Quartz29/2006
Best regards,
  Paul

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