Does anyone who wins a live arena tournament not cheat?

Example player rated 850 (at the end of tournament scores 18.5/19.  Not to sound negative but the odds of a player at that strength, or any strength for that matter not making at least 1 blunder that costs a game in 19 consecutive games seems a bit sus to me. This was 5 min blitz. 

About half of the winners of non-increment blitz and rapid tournaments are clearly and obviously playing fairly.

There has been a lot of discussion in various subs about pairing methods in Arena tournaments.  Generally, a player rated 850 is paired not against players with the same score that he has, but with players who have the same or similar rating as he has.  So an 850 player who is having a good day can easily win one of these events.

You might want to check out the results of the 3/2 Arenas at the same time you look at the 3/0's.  There is rarely an issue in 3/2.  Why, I can't say.  By rule.

I want to believe that is true but 19 games with no loss, 18 wins and 1 draw. I doubt I could ever achieve that level of consistency playing against +-200 rating point opponents 

I think if you read more carefully, I said that "About half of the winners" are playing fairly.

Not true... Chess.com has never changed their match making. it's always been the same, only some slight tweaks. Match making is on score so the odds of an 850 or lower wining are basically impossible... I know this because 2 years ago someone rated 451 beat me and gained 18+ points for wining and won the tournament. (They were swiftly banned for cheating).

Matchmaking is not based on score in arenas. They generally pair you with the closest rated person to you that's also searching for a match.

About half based on what data?

It's my own.  I've been focusing on 3/0 Arenas over the last week or so, looking for top five finishers that appear suspicious.  If you click on Play > Tournaments, in the right hand sidebar there's an option to look at completed live tournaments.  Click on that, and you can check tournament results for God only knows how long.  I filter it down by "Blitz" then start checking.

Let me pause to say that yes, I know I have no life.

On Sunday I checked out all twenty three (there is a one hour break every day).  Eleven of 23 winners were eventually banned, I had reported six of them.  There were one or two that were iffy.  One person who won was a GM with a 2800 rating.  No question about him.  A couple were people rated below 900 who had beaten a bunch of similarly rated players.

When you look at the individual games, there is no question regarding cheating.  These are games that begin 1. e4 e5; 2. Nf3 Qh5, or something equally horrible.  The person who won was playing awful, but nowhere near as awful as his opponents.

When you see someone who goes 15-0-0, okay, be suspicious, maybe look further.  But when it's 15-2-6, I would suggest you'll never see one of those players that get banned.  That's just what happens when you get 1000 people in one of these tournaments.  A couple of people just happen to do really well, regardless of their strength.

Hi, 

Please report suspicious players and not make posts on the forums and the fair play team will check them out 

https://support.chess.com/article/209-how-do-i-report-someone