The Uniqueness of Chess Games.

Sometimes when I'm playing chess I wonder if this exact game has ever been played before. I mean by anyone any time OTB correspondence or online, in the entire history of chess. At first it sounds like the chances favor that it would have been, based on the number of games that have been played. But if you consider the mathematics of calculating the number of possible variations that multiply with each move it starts to favor the other side of the argument.
Take my last game for example. Really doubt this has ever happened before. lichess.org/J40Gz0oc#0
I think one factor it depends on is our level. Good players tend to play known established lines more often, up to a point. And playing style.
But overall, how often do you think it happens you play a unique game that has never occurred before?

Most games are unique at some point.

I've played games which I've played before.

If you play the truly best move, in you opinion, you should continue to play the same move in the same position, assuming that you haven't improve significantly. This means that the chances of repeating a game is very low.

@jonesmh It sounded like you were arguing for the side that games do get repeated, until your last sentence.
That's what I was just thinking about now. @lovlas It's amazing if most games are unique when you consider that the conditions in a chess game are always identical. The pieces start in exactly the same starting position each time and there are no other factors like weather or differences of playing field. And that a few certain moves are HEAVILY favored over others eg compared to 1. e4 1.f3 is almost never played, and that it's the same subset of people that play chess out of the whole world's population based on the opening theory and books etc that they've read which doesn't change very often.

Why dont you just say: "Hey dudes, i played a nice game and i want everyone admire me for it".

Had a thought about "unique chess games" once this position arose.

@Klartext Totally not true. In fact while I was playing this game I was thinking about this stuff and thinking of making this post, which has been the the back of my mind for a while.
So I was almost disappointed with the way the game ended because I knew someone might make an accusation like yours, but then I looked at the graph and I made quite a few inaccuracies and the idea for this post has been in my mind for a long time so I thought what the heck. So go ahead and think what you will, but this has been a question that I've pondered for a long time.
@circle_VIII haha, you too I see. Wait, I think I've played that game before, on both sides.

@lovlas or other Lichess mods, since people are accusing me of just wanting to have a nice game admired, could you delete this thread? I'll repost it in a few weeks with a less beautiful but equally unique game as an example. Because this is a question that seriously fascinates me, I was hoping I could get someone who could give some maths for it.

You want mathematical probabilities or ideas about the number of positions?

@President_DonaldDuck well, if that was not your intend, then the game you posted is not relevant to the topic.

www.google.com/search?q=chess+games+with+identical+moves

has lead me to

chess.stackexchange.com/questions/18716/longest-number-of-moves-that-have-been-identical-in-two-independently-played-gam

and this links to www.chess.com/forum/view/general/identical-chess-games-at-master-level

where eg.



is given. This has been given draw in 20 games according to my database.

The following game has been given draw 393 times according to my database (found at www.chess.com/forum/view/general/no-two-games-alike) Edit: That is not correct, without move transpositions it is just 94 games (with exact that move order).



I am also sure that much longer and decided games have been played twice but cant give any concrete examples. I once read something about it somewhere but cant find it any more.