Undestanding chess is hard...
and (grand) masters are sometimes not very helpful :-)
Look at the analysis of the same game, MVL against Hou Yifan at Grenke 2017, but on two different sites:
- https://www.chess.com/news/view/aronian-new-leader-at-grenke-7098
- http://en.chessbase.com/post/grenke-classic-2017-levon-takes-the-lead
One key move 53. b3 is judged with
- an exclamation mark here on chess.com
- a question mark on chessbase
Annoying ;-)