Yu vs Vidit - 9th Hainan Danzhou GM 2018 - Round 4

While playing through the game, scroll slowly so that when you get to the questions you can put some time on the clock (ten to fifteen minutes) and try and find the solution.

Yu,Yangyi (2762) - Vidit,Santosh Gujrathi (2718)

9th Hainan Danzhou GM 2018 Danzhou (4), 30.07.2018

1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Nf3 c5 8.Be3 Qa5 9.Qd2 0–0 10.Rc1 Nd7 11.Bd3 D85: Exchange Grünfeld: Unusual White 7th moves and lines with 7 Nf3 

11...e5 12.d5 f5 

XABCDEFGHY
8r+l+-trk+(
7zpp+n+-vlp'
6-+-+-+p+&
5wq-zpPzpp+-%
4-+-+P+-+$
3+-zPLvLN+-#
2P+-wQ-zPPzP"
1+-tR-mK-+R!
xabcdefghy

13.Qe2N [13.Bg5 Nf6 14.Nxe5 Nxe4 15.Bxe4 fxe4 16.Nc4 Qa6 17.Ne3 Bd7 18.c4 Rae8 0–1 (49) Vovk,Y (2600)-Zubov,A (2604) Lvov 2017] 

13...fxe4 14.Bxe4 Nf6 15.d6 Nxe4 16.Qc4+ Kh8 17.Qxe4 Bf5 18.Qd5 Qa4 

XABCDEFGHY
8r+-+-tr-mk(
7zpp+-+-vlp'
6-+-zP-+p+&
5+-zpQzpl+-%
4q+-+-+-+$
3+-zP-vLN+-#
2P+-+-zPPzP"
1+-tR-mK-+R!
xabcdefghy

19.Ng5 

What would have been wrong with 19.Bxc5 in this position instead of the move played?

00000

[Much weaker is 19.Bxc5 Be4³] 

19...h6 20.Ne6 Bxe6! 21.Qxe6 Qc6 22.Qxg6 Rf6 23.Qg4 Rxd6 24.0–0 c4 25.Rfd1 Rd3 26.Rxd3 cxd3 27.f3 Rd8 28.Qe4 d2 29.Rd1 Qxc3 30.Kf2 b6 31.a4 Qa5 32.g4 [32.Qc6±] 

32...b5 

XABCDEFGHY
8-+-tr-+-mk(
7zp-+-+-vl-'
6-+-+-+-zp&
5wqp+-zp-+-%
4P+-+Q+P+$
3+-+-vLP+-#
2-+-zp-mK-zP"
1+-+R+-+-!
xabcdefghy

Black missed the chance to retain positional equality here. Can you find the move?

00000 

[32...a6!= remains equal.] 

33.axb5! Qxb5 34.Rxd2 Rxd2+ 35.Bxd2 Qb2 36.Ke2 Qb5+ 37.Qd3 Qb6 38.h4 

XABCDEFGHY
8-+-+-+-mk(
7zp-+-+-vl-'
6-wq-+-+-zp&
5+-+-zp-+-%
4-+-+-+PzP$
3+-+Q+P+-#
2-+-vLK+-+"
1+-+-+-+-!
xabcdefghy

38...a6 [38...a5²] 

39.h5 Qe6 40.Bc3 Kg8 41.Qe4 Qa2+ 42.Ke3 Qe6 43.Qb7 Qc4 44.Qb4 Qc6 45.Qa5 Qf6 46.Qd5+ Kh8 47.Ke4 Qf4+ 48.Kd3 Qf6 [48...Qc1± might work better.] 

49.Ba5 

XABCDEFGHY
8-+-+-+-mk(
7+-+-+-vl-'
6p+-+-wq-zp&
5vL-+Qzp-+P%
4-+-+-+P+$
3+-+K+P+-#
2-+-+-+-+"
1+-+-+-+-!
xabcdefghy

49...Qf8? [49...e4+ 50.Kxe4 (50.Qxe4 Qd6+ 51.Ke2 Qh2+ 52.Kd1 Qd6+ 53.Bd2 Kg8+-) 50...Qb2] 

50.Qd8 Qxd8+ 51.Bxd8 Kg8 52.Ke4 Bf8 53.Ba5 Bd6 54.Kd5 Bb8 55.Bc3 Ba7 56.Kxe5 Bb6 57.Kf6 Be3 58.Kg6 Bf4 59.Bb4 Bc1 60.Bd6 a5 61.f4 a4 62.f5 1–0