Usually you cant tell in blitz; it rarely happens. In standard, you would be able to tell. If someone is playing better than garry kasparov at 1200 ELO, then they are probably cheating ;)
How do I know when someone is cheating?

Dude... You're 800 ELO... The players you are facing are going to be around 800 ELO. If they used Engines (roughly 3000 ELO) then how would it be possible their ratings are so bad? :p use logic!

My point is that unless the person you're playing has a reasonably high rating (over 1000 is a good place to start... Lol) there is basically a 0% chance they are using any sort of cheating mechanism.
Engines are rated 3000 after playing 5 blitz games on chess.com? Who knew?
It also doesn't follow "logically" that on an open seek, an 800's opponents will necessarily be rated 800. A logic fail, followed by a logic call out. You don't see that every day.
Over at the previous site I played on, it was very common to see 1100's (and thereabouts) banned for cheating. Why? They wanted to make damn good and sure they didn't lose to 800's, even though they felt it was okay if they lost to people with higher ratings. Losing to a bad player was humiliating, while losing to a good player was all right.
Engines are rated 3000 after playing 5 blitz games on chess.com? Who knew?
It also doesn't follow "logically" that on an open seek, an 800's opponents will necessarily be rated 800. A logic fail, followed by a logic call out. You don't see that every day.
Can anybody out there translate this for me? Thanks.
Over at the previous site I played on, it was very common to see 1100's (and thereabouts) banned for cheating. Why? They wanted to make damn good and sure they didn't lose to 800's, even though they felt it was okay if they lost to people with higher ratings. Losing to a bad player was humiliating, while losing to a good player was all right.
You mean they lose to somebody a couple of times and get mad basically because they hate their lives and then use an engine in a re-match? What you posted is obviously BS.

An 1100 is not going to have to use an engine to beat an 800.... That's the stupidest thing I've ever heard. The players getting banned on this site for engine usage are always 1700+ (and I've never encountered anyone I suspected of engine use, even when playing 18 and 1900+ players). To put it quite bluntly, it's online chess, who gives a shit?
If you go back and look over a game (especially one where you lost to someone playing "perfect engine moves"), I guarantee you will find obvious mistakes from both sides.
Engines are rated 3000 after playing 5 blitz games on chess.com? Who knew?
It also doesn't follow "logically" that on an open seek, an 800's opponents will necessarily be rated 800. A logic fail, followed by a logic call out. You don't see that every day.
Can anybody out there translate this for me? Thanks.
Not very good at English? Because I write professionally, and can vouch for the quality of that paragraph.
Over at the previous site I played on, it was very common to see 1100's (and thereabouts) banned for cheating. Why? They wanted to make damn good and sure they didn't lose to 800's, even though they felt it was okay if they lost to people with higher ratings. Losing to a bad player was humiliating, while losing to a good player was all right.
You mean they lose to somebody a couple of times and get mad basically because they hate their lives and then use an engine in a re-match? What you posted is obviously BS.
My God, is there anyone on this site that isn't a complete bumblefucking moron?
The simple fact is, people don't cheat. People your rating probably can't even spell "cheat", much less "chess".
An 1100 is not going to have to use an engine to beat an 800.... That's the stupidest thing I've ever heard. The players getting banned on this site for engine usage are always 1700+ (and I've never encountered anyone I suspected of engine use, even when playing 18 and 1900+ players). To put it quite bluntly, it's online chess, who gives a shit?
If you go back and look over a game (especially one where you lost to someone playing "perfect engine moves"), I guarantee you will find obvious mistakes from both sides.
He's an "1100" because he uses engines to beat low-ranked players, nitwit.
Christ, you have no business ever using the word logic in a sentence, ever again.
My God, is there anyone on this site that isn't a complete bumblefucking moron?
Hi, I'm replying to your ad. for somebody who isn't a "complete bumblefucking moron". What is the pay?

Engines are rated 3000 after playing 5 blitz games on chess.com? Who knew?
It also doesn't follow "logically" that on an open seek, an 800's opponents will necessarily be rated 800. A logic fail, followed by a logic call out. You don't see that every day.
Translation:
1. It is very likely that an open seeker (a person seeking for a match) with a rating of 800 will find another with 800 rating as well.
2. This implies that the user I have faced may have used an engine, unlikely, but it is possible because then that was just the starting point of the cheaters use of winning.
But number 2 is unlikely.
Still, I thought the lower level players I were to face would be complete amateurs (even more than I am), apparently I have much to learn.

Lol, Mickey, your logic makes no sense and is simply a waste of time for any of us to read.
Why do you even come on this site (I see no ratings on your profile)? Do you have nothing better to do than go into the chess.com forums, spout nonsense, and then flame players who are far stronger and know far more than you about all things chess? Stop being stupid. If you can.
Basically.......I play Blitz and lose.
Okay, most likely he is better than me.
But how could I be sure he doesn't have a second computer over there cheating? Or having a program open or whatever?