Why do high level chess players consistently make really strange looking moves?

That McShane game you posted?

I don't know... it doesn't seem that strange. Sure the position is totally non standard, and moves 10-12 are weird, but that's just a few moves, I think most of the moves make sense.

Reminds me of a train wreck set to music.

Those are strange moves for who believes in logic

Those are smart moves for who believes in situation

They make strange-looking moves because they're strange-looking people.

For games that looks like a beginner and full of weird moves you need someone like Michael Basman

It's not nice of them at all, no.

no i mean u calling them strange-looking people

no i mean u calling them strange-looking people

they're strange off the board as well

https://www.chess.com/forum/view/chess-players/chess-maneuvers-off-the-board

"principles are for chessnobs with little to no playing ability, which is the vast majority. so it’s easy to sell them books and sh**"

That's absolute nonsense. All the top players have a deep understanding of chess principles, and most of their moves adhere to those principles. But their understanding of chess principles goes a long way past a simple set of rules that you could fit on an index card. They understand the differences between open and closed positions, and the know which principles apply to each type of position, And they also understand that chess is a concrete game! General rules can always be overruled by exact calculation

Gosh, strangeness seems to permeate their whole existence.

you can argue that the kings square are weakened but is it really. Black is the one getting play. His king is surrounded by more pieces than the attackers so its not really weak. Its only weak if it can be attacked

you can but why would you? that just opens up blacks g7 bishop. Also there is no imbalance or advantage for you to use to attack black. No side can attack unless you have advantage. Therefore there is nothing to be afraid of

Ah yes, my favorite example: the lovely czech benoni!

and another case:

cough 5.Nxf7?? cough

Because they're looking 6 or more moves ahead, and thinking about the position they want to be in at that point.

     The analyses of different specific positions here reveal the answer to the original question. The "basic principles" are simply general guidelines; every position must be analyzed for its own particular tactical and positional possibilities. The moves very strong players make that look strange to us lesser players are played because they are superior in that position. A "minor" change in pawn position or piece placement may make a more "normal" move preferable in what looks like much the same position. Sometimes a strong player will deliberately make a "strange looking" second or third best move in order to create an unbalanced less-drawish game, perhaps because their standing in the tournament or match dictates a win at all costs approach. And even strong GMs  overlook things sometimes. But usually these "strange" moves are better, although the reason for their superiority won't be clear to us lesser players until several moves further into the game.

Whenever you see titled players in a game, the chances are high that they've played that position (or similar positions) many times before. Hundreds of times, likely. Perhaps thousands of times.

So they've learned, through repetition and analysis, what the most common candidate moves will be. Often these moves may look strange, especially if you don't have experience with similar positions, yourself. Usually they have tactical or positional implications (things that aren't always obvious at first glance).

So, long story short: the strange-looking moves are a product of experience, analysis, and positional understanding. They aren't thought up on a whim, in the spur of the moment. They're usually moves that have been looked at and studied before.