What does a 1800 rated player do/know that a 1600 doesn't?

How does a 1600 rated player become a 1800? What do you have to do differently to continue to improve? What do 1800's do that 1600's are not?  Thanks.

an 1800 knows more patterns(checkmate patterns, openings, traps, endgames). (more

probably more random things

easy: how to consistently beat 1700s  

unfortunately there isnt some 'one magic thing' at any level of chess.  Higher rated players make fewer mistakes, miss fewer tactics and advantages, know more openings and endings, maybe see one more move in combos, etc.  And, numbers mean little too.. Ive beaten 1800s, and lost to people far below my rating.   At this point, to start beating 1700s, try playing some and seeing why you lost (if you lose, of course).   

If I had to bet odds and guess, I would say its more likely endgame.  1500-1600s frequently allow trades or play that puts them into a lost endgame and they don't even know it for several moves, then its like ".. oh.. this can't be won now...".   For me, also trying to break back into the 1700s, I find that 85% or more of my losses are directly related to missing a move the opponent had, and those range from stupid forks to sharp unexpected responses when I thought I had the upper hand.  

There is no general answer because every player has different strengths and weaknesses. A 1600 could easily be better in opening / endgame knowledge or tactics than a 1800 but then be much worse at any other part of the game.

Therefore you have to analyze your games, find out what your weaknesses are and work on them.

This does sound like me.  Thanks.

1) The fundamentals of positional-strategic chess...

Good Positional Chess, Planning & Strategy Books for Beginners and Beyond...

https://www.chess.com/blog/RussBell/introduction-to-positional-chess-planning-strategy

2) How to more effectively use pawns...

Pawn Play and Structure - for Beginners and Beyond...

https://www.chess.com/blog/RussBell/chess-books-on-pawn-play-and-structure

3) More about the endgame...

Opposition - The Most Important Endgame Concept...

https://www.chess.com/blog/RussBell/opposition

Right now 1700-1850 I'd say is inflated, passing 1700 was the hardest thing for me. Anyways, as long as you have beaten people at that rating multiple times before, it's a matter of consistency, not skill, not really. Study the endgame, that's where a lot of people (including a couple 2000s, witnessed @Moonwarrior_1 lose a winning endgame in rapid -_-) mess up...

Generally speaking, the difference in overall knowledge between an 1800 and a 1600 is less than you'd think.
I've learnt a few more positional concepts during my rise from 1600 to 1800 as well as planning, but honestly, when I analyse my games, almost every game is decided by raw calculation in some form or another.
I've just become that bit more sharper, a bit better at recognising patterns, a bit better at calculating one move deeper than before. Being that bit more diligent when you lose an opening, that you analyse the database to see what the proper move is supposed to be and why - to avoid doing the same instinctive move again, etc.

I don't think it's such a sharp difference between 1600's and 1800's. They're both players that will have some defects in their chess understanding. It's hard to generalize. One thing that I've noticed in the past though is that some 1600's tend to play somewhat 'unreasonable' chess. For example always attacking even when the position doesn't quite call for it. I would expect that style of chess to work well versus 1400-1500, but not against 1800-1900. So maybe the difference between a 1600 player and an 1800 player could be that around 1600 you start to get punished for bad habits and around 1800 you've done away with the biggest bad habits that you've picked up.

"Players under 1800 blunder almost every move" - Carlsen
An 1800 player blunders less than a 1600 player.
An 1800 player checks his intended move is no blunder before he plays it.

There is no good answer to this. Even among equally rated players there are differences. The obsession with rating is very prevalent in online chess because it is constantly displayed in front of your face. People should just take serious look at their own games to find out what they actually have to work on, if possible a stronger player should give them feedback on their analysis.

In OTB chess especially if you mainly play OTB team competitions you don't get to know your rating until the next season. During the season you only play your games and you don't actually know what rating you are. This is why rating was never on my mind. I rather focused on more important areas.

In online chess, there are many players who exclusively play online which means they grow up having a number going up and down in front of their face after every single game. As a consequence there is not a single day going by without one person asking any rating related questions.

Focus on improvement not rating. Labeling yourself a 1400 also limits yourself because you clearly state with your own words that you are this specific rating which isn't an accurate representation of your skills anyway.

I agree, focusing on rating is not the best way to improve.  Analyzing my own games for mistakes is probably the best thing for me right now.

Hard to say any single element between a 200 point gap, but if I had to pick a single thing, it is probably expanded "positional knowledge." 

At least for myself and a few chess.com friends I've witnessed improve: 1600 chess.com rating seems to be around the time where the player begins to really grasp positional concepts like weak squares, weak color-complex, or outposts. 

By 1800, it seems to be a bit more refined knowledge to these, but also adding a few pawn structure considerations and more or less forcing weaknesses etc.

Again, tough to say any single difference with 200 rating interval, but this would be my response if I had to pick one thing different between most 1600 and 1800 players I've observed.

basically to get from 1600 to 1800 you just have to get better all-round at chess, there is no one thing! It is just everything...

Wow... thank you.

Your comment was very useful for me as I myself was 1600 some time ago.

And yes yes yes... I suspected that I lacked Chess positions understanding.

And I rushed in crazy attacks at any first chance I only had. )

No I'm sorry 1900s last until move 8 they get to #7, 1600s get to 5! From what I remember...

I don't know... that seems like an OTB answer, because I think that's around the time players try to decipher the nature of the position instead of just playing whatever they want.

I wouldn't expect that difference between 1600 to 1800 online (blitz or daily or anything else).

It seems that how much high the level (ELO) faster is the move.

A move that me, a 1200 ELO, take a minute to create, a GM takes 5 seconds.

The memory of a 1800 player has more data about how to move, defenses agains traps, and oppenings and so on than a lower. To reach to 1800 player must play and win more times than a 1600 one.

This suggests that the main thing to considere is not the reasoning, but the memory. Who knows?

But I think that from 1800 to 1600 is few difference to compare.
(My opinion only)