Puzzle of the week #285

Submitted by Eugen on Sun, 11/01/2015 - 23:44
Level
4-Rook
Chess Diagram
[Event "Puzzle #285"][Date "2015.11.01"][Result "0-1"]1. e4 e6 2. d4 d5 3. Nc3 Nf6 4. Bg5 Be7 5. e5 Nfd7 6. Bxe7 Qxe7 7. f4 a6 8. Nf3 c5 9. Qd2 Nc6 10. O-O-O O-O 11. dxc5 Nxc5 12. Bd3 b5 13. Qf2 f5 14. exf6 Nxd3+ 15. cxd3 Qxf6 16. g3 b4 17. Na4 e5 18. Kb1 exf4 19. Nb6 fxg3 20. Qc5 g2 21. Rhg1 Bg4 22. Nxa8 Bxf3 23. Nb6 Bxd1 24. Nd7 {Stop here and analyse the position before moving on} 24... Bc2+ 25. Kc1 Qf1+ 26. Kxc2 Rf2+ 27. Kb3 Qxd3+ 28. Ka4 Qc2+ 29. Qxc2 Rxc2 30. Kb3 Nd4+ 31. Kxb4 Nf3
First replay the above game and then return at move 27 for white. Your tasks:
a) When did the opening end and middle game begin? Explain
b) List all good moves for either side
c) List all bad moves for either side
d) How could have black won the game in case of 24... Bc2+ 25. Kxc2 ...?

Total available points for this puzzle is 30. The answers will be published next time together with puzzle #286.

Puzzle #284 solution:
Game Mrdja - Gleizerov, Zagreb 2011. The best responses:
a) Cody: "The middle game started after white did 12. Bd3 ... He developed all his pieces except the h1 rook and he castled"
b) Good moves were:
White: 16.Nfd4 ... and 17.Kb1 ...
Black: 10... Nxc5, 14... b3, 15... Nb4 and 25... d4
c) Bad moves were:
White: 13.Rhe1 ..., 22.Nd6 ... and 26.Qxd4 ...
Black: 20... Ra6
[Event "Puzzle #284"][Date "2015.10.19"][Result "0-1"]1. e4 e6 2. d4 d5 3. Nc3 Nf6 4. Bg5 Be7 5. e5 Nfd7 6. Bxe7 Qxe7 7. f4 O-O 8. Nf3 c5 9. Qd2 Nc6 10. dxc5 Nxc5 11. O-O-O a6 12. Bd3 b5 13. Rhe1 b4 14. Ne2 b3 15. axb3 Nb4 16. Nfd4 a5 17. Kb1 Ncxd3 18. cxd3 a4 19. bxa4 Rxa4 20. Nc3 Ra6 21. Ncb5 Bd7 22. Nd6 Rb8 23. Rc1 Qd8 24. Nb3 Qb6 25. Qe3 d4 26. Qxd4 Ra1+ {White resigned because of the following threat} 27. Kxa1 (27. Nxa1 Qxd4) 27... Qa6+ 28. Kb1 Qa2#

Correct solutions:
Yakov, Cody - 20 points
Bradley - 17 points
Deryk, Terry - 15 points
Benjamin - 13 points
Coco, Ronald, Aaron - 10 points
Jalen - 4 points

Standings:
Cody - 97 points
Coco - 82 points
Yakov - 62 points
Bradley - 60 points
Deryk - 59 points
Terry - 56 points
Jalen - 55 points
Benjamin - 51 points
Andrew - 36 points
Aaron - 35 points
Ronald - 28 points