I already know that it doesn't count any games with 0 achievements, but I've deleted some games with unlocked achievements from my Steam profile using help.steampowered.com.
I want to know if these removed games still count to the Avg. Game Completion Rate for my profile.
Best Answer
Based off of this Steam post, it looks like they still do:
I also found a rather detailed Steam Guide about the Average Game Completion Rules and it states:
It goes on and says:
Bottom line - yes they will still factor into the average, which in my opinion makes sense still since at one point, you did play the game.