Since i experience the same issue since june (didnt game much) i want to share
my system info.
I am on Ryzen 2600X, Vega 56 Pulse, Strix B450. Using Arch 5.1.
Tested every Windowmanager i know , tested also 60Hz and 144Hz. The crashes are
totally random. I only play Dota 2. Last friday i played like 6 games in a row
without a single issue. The day after i crashed like 7 times per game. Always
have to press reset on my PC. 
Is it know that hits issue related to a kernel or mesa update? I mean it wasnt
always like this no?