How to make Steam not count some games towards "Avg. Game Completion Rate"?

In Steam, some of the Showcases show the Avg. Game Completion Rate. This takes into account the percentage of achievements you have in average of all your games.
Is there any way to make it not count some games? Sometimes you install games (specially free ones) and find them quite boring and stop playing them. It feels a bit annoying to see a low average due to them.
Best Answer
Unfortunately - no. There is no way to remove the "ghost" of achievements affecting your AGC ratio on Steam. Using some kind of unlock/relocker tool to wipe a game's achievements will actually only harm your AGC because if you have ever had 1 achievement in a game, it will forever affect your AGC and by taking yourself to 0%, you have only lowered it. Valve will not wipe/clear achievements for you if you contact them via support. Games where the DEVELOPER chooses to remove some or all achievements will properly update their affect on your AGC, however.
All of this confirmed via the complex stats on the https://completionist.me tracker and through extensive testing by the 100Pals official Steam achievement hunting community: https://www.discord.me/100Pals
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How does Steam calculate avg game completion rate?
A total of all your earned achievements divided by the total number of possible achievements in all of the games you own. The number of games that you've 100% completed (a.k.a. Perfect Games) divided by the total number of games in your library.How is average game completion calculated?
Games you haven't played do not count. If you have earned 200/400 in one game and 5/10 in another, your average completion rate is 50%. Originally posted by Canti: If you have earned 200/400 in one game and 5/10 in another, your average completion rate is 50%.Can you remove a game from your achievement list Steam?
To permanently delete a game from your library, click Help > Steam Support. Click the game you want to delete. If you've played it recently, it will appear at the top of the list.Why do some Steam achievements not count?
Then on June 2018, Valve decided to restrict more features from newly released games, this time the restrictions being: Limit the game's total number of achievements to 100. The number of achievements won't count for the total number of achievements.How to Instantly Unlock Any Steam Achievement
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Answer 2
There's no legitimate method that you can use however there are third party tools available that you can use to re-lock achievements. So you can set the earned achievements for any given game to zero but I'm unsure how long/or if this will effect the showcase in question.
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