What accuracy would you consider suspicious?

I've met 2 players with unusually high accuracy.  One with an accuracy in the upper 90's, who was found to be cheating.

Another with low 80s, which I've never seen in my bracket.  This one was suspicious to me.  The person played fairly fast for someone with such a high accuracy.  The mid-game is the point that I grew suspicious.

Anyway, my thought is that someone in the 80s or, especially, the 90s is suspect.

Anything over 100 is suspicious other than that, it really depends upon the match.

Many times when I check players rating stats, many fluctuate 300 ratingpoints up and down in sharp climbs and falls. To me that is not natural.

lol, yeah. I'd be a little suspicious too.

That is from playing too much it magnifies the drop in performance

90+ is suspicious I'd say, and 95+ is almost certainly cheating.

Anything over 100

I wouldn't say accuracy is sus. Its if the opponent magically knows all the theory that is concerning.

This seems backwards. Theory, by definition, is something a lot of good players know, while few players can find the best move in this position as black.

Is the best move Queen takes g3? It seems really simple because after hxg3, it's h2, kh1, and Nf2 mate

You are mostly correct, but after 2. ... h2 black doesn't play 3. Kh1

Are you telling me that some people cant find that...?

They play kf1? It's still a mate, you promote to queen and it's mate in a couple moves

If they are cheating and their rating is still below 1000 they are clearly doing something wrong...

That puzzle was pretty easy I only messed up once and I’m only 1k elo

I made no mistakes, I would consider this as a 1200 elo puzzle, but I'm only 1600 so I could be wrong

I solved it but I made 2 mistakes

a single game is not suspicious. usually signs of cheating are from consistent high level play, consistent usage of time (human players tend to think longer in difficult positions), and high winrates.

Anyone can get a 90% accuracy in the occasional game if they are focused and get a good start. I have had a few but my accuracy in general is around 70s. My rating has been between a 200 point range and I play on and off. I hope to get better but have dropped off. Remember that rating is often a range so you get people playing above and bellow their most recent number is normal. Also you might stumble into a familiar pattern they know better than you.

Btw, Almost every english game is guaranteed to have 90% accuracy.