Sergash: According to Chessbase, Grubert was rated 2170 when he played this game. He is not a FIDE master.The first error in the game was <11...b6?!>. 11...dxc4! 12.Bxc4 b5 13.Bd3 Nd7= Alexander Khalifman (2485) vs Igor Belov (2200), Moscow (USSR) 1985, Group B, draw.
Then <13.c4? Nc6=>, while 13.Rb5! Bc7 14.h3 a6 15.Rxd5! Qxd5 16.hxg4 Nc6
Semen Dvoirys (2535) vs Eduardas Rozentalis (2520), Lviv Zonal Tournament (USSR) 1990, draw.
<14...Nxd4?! 15.Bxh7!
> 14...Nb4! (Cristoph Maeurer (2215) vs Viesturs Meijers (2380), 5th Staufer Open (Germany) 1993, round 3, 0-1) 15.h3 Bh5! 16.Bc4= transposing in Bostjan Markun (2250) vs David Habjanic, Slovenia U18 Championship 1993, draw.
<17...f5?! 18.Qxf3
> Better was 17...Kg8 18.Qxf3 Re8
/
Komodo 9.2 64 bits.
<18...Be5? 19.Ba3
> The first serious mistake by Carlsen, after which he is losing. While evident in appearance, he should have played 18...Qh4 19.g3 (or 19.h3 Qe4 20.Qxe4 fxe4
/ Komodo 9.2 64 bits.) Qg4 20.Qxg4 fxg4 21.Be3
Komodo 9.2 64 bits.
<20.Bxd6?!> Black could have some hope of saving the game here. White should have played 20.Rbd1!
Komodo 9.2 64 bits.
<21...g6? 22.Rc6!
> The only chance was 21...Rad8
/
Komodo 9.2 64 bits.