chess problems from ps 11

 1. Austin Tang (445) is an enthusiastic, hard-working new 7th grade player. Where should he, white, have gone here?

 2. Kevin Marin had a breakthrough tournament today, winning 3/4 in fine style. This was the game he lost, making the critical wrong choice here. What is white's best /worst move?

3) Yuxin Zhao used to be a lacksidasical 900, shrugging off blunders and losses. Suddenly she's super- competitive, has learned a lot of openings, calculates vicious traps, and becomes 1300. In the above position, she's black in a caro kann, and has unfortunately shut in her light squared bishop, but she gets a chance here to solve her positional problems here.

4) Yuxin is down an exchange later in the game, but her opponent tried to trade rooks here with 30. Re1. How did black win?

5) Jorge Quiroz (1270) got this position as white, and I felt like he should have something, so I wrote it in my notebook and fritzed it. White has two ideas to try: what works?

Jorge Quiroz

1. 5. Ng5! wins at least a pawn by attacking f7. Black's best is 5...Be6.

2. Kevin played the clever by faulty 28... Rb8, hoping for 29. Qxc4 Rxd8 30. Kh7 bxc4, but losing to 29. Qd6+.

3. Yuxin should play 9... Nb4 10. Bb5 and then I suggested 10... Bd7, trading off the bad bishop, but fritz prefers 10... Qa5, with variations like 11. Nc3 Ne4.

4. She won with 31... Ba5+ 32. c3 Bxc3+ 33. bxc3 dxc3+ 34. Kd1 c2+ 35. Kd2? Rxe1 36. Kxe1 c1=Q+

5. Idea 1: 9. Ne5! Bd6 10. Qa4 Bxe5 11. dxe5 Ng4 12. f4 a6 13. Bc6 Rc8 14.
Bxd7+ Qxd7 15. Qxa6 O-O 16. h3 Nh6 17. Qxb6

Idea 2: 9. e4!

9... Nxe4?? 10. Ne5 Nef6 11. Bg5 Be7 12. Bxf6 gxf6 13. Nxd7

9... Bxe4? 10. Nxe4 dxe4 11. Ne5 h6 (11... Be7 12. Nc6 Qc7 13. Nxe7 Kxe7 14. Bd2 Kf8 15. Rc1 Qd8 16. O-O +/-) 12. d5 exd5 13. Nxd7 Nxd7 14. Qxd5 Bb4+ 15. Kf1 Rc8 16. Bf4 (16. Qxe4+? Qe7 =) 16... Qe7 (16... a6 17. Qxe4+ Be7 18. Bc6) 17. Rd1 O-O 18. Bxd7+-)

9...dxe4 10. Ne5 The threat is 11. Bg5 Be7 12. Bxf6 Bxf6 13. Nxd7

If 10...Be7 11. g4 Bg6 (11... Bxg4? 12. Bxd7+ Nxd7 13. Nxg4) 12. g5) )

If 10...a6, 11. Bc6 Rc8 12. Bg5 and black has to sack the exchange: 12...Rxc6 13. Nxc6 Qc7