Is There Always a Correct Move?

I understand that chess is still not mathematically solved yet, but am curious if in theory there is always a singles best/correct move? 

Sometimes it is obvious such a move exists (e.g., a checkmating move), but other times it's not so clear what the absolute best move might be in any given situation.  Nevertheless, I wonder if there IS still a correct move (even if we don't know it )? 

Hopefully my question makes sense. 

(p.s., I wonder if there can also be more than one correct move? )

What would be the best move here, then?

No.  That is the whole premise behind zugzwang.  Putting your opponent in a position where any move he makes is a bad one.  If any move will actually lose the game, then all moves have a true value of zero, meaning there is no "best" move in such a situation.  Which, in turn, means the best move is probably resignation.

In some endgames, there are situations where two or more moves may be equally good/correct. It is not obvious to me whether this is true or not earlier on.

There may be no good (i.e. winning) move in zugzwang, but they may be equally "least bad".

@quisi-LEGAL moves :)

Although iam no game theory expert, i believe that there should always be a "least bad" move (i.e., maximin solution). It is possible that several moves may be tied for least bad. Howver, i am not sure that we have algorithms that are practical given the current state of computer hardware technology to always calculate the least bad move with certainty in all scenarios.

fburton wrote:

There may be no good (i.e. winning) move in zugzwang, but they may be equally "least bad".

if they are all bad moves, might as well just resign on the first move

Least bad in the game theoretic sense does not mean that the move is a bad move. In fact, the least bad or least worst move could lead to a forced mate of your opponent. The term means that you examine the worst possible outcome for each move and select the best outcome out of the worst outcomes in each line. In other words, you assume your opponent will play optimally.

qiusi wrote:

if they are all bad moves, might as well just resign on the first move

then offer draw on the first move

Sometimes, the best move loses. That will only happen if you have already made mistakes though. With best play, chess is a draw.

In the vast majority of positions, there are several "correct" responses available. So while objectivity is a laudable goal in chess, some subjectivity will always creep in when deciding between two different paths that both look about equal.

I think that there is always a best move (or several best moves). That doesn't mean that they will be winning moves.  Some of the moves will just the the lesser of two evils.

The only exception is when there is a forced or unavoidable mate or loss of material.  But then this would be a result of previous moves that were not optimal.

You recognize that chess is solvable.

You wonder if there is a best move.

Reconcile that for me.

Yes.

what is the optimal move here

Depends on how you look at it.

Any particular chess game can only end with one of three possible results: either White wins, or Black wins, or the game is drawn.

One could argue, then (and some people do take this position), that any move that does not degrade the game state (from a winning position to only drawing, for example) is just as good as any other move that does not degrade the game state... both moves will eventually give the same result with best play (in our example, a win).

Others argue - and I'm in this camp - that there is indeed a difference between one winning move and another, even though both lead to the same result "with best play". The difference is that the line which leads most directly to the win is the line most likely for you and I to play correctly. People aren't computers, and some moves are easier for us to find than others.

Aren't you a bit late? This thread was already quite old 10 years ago.

I considered myself quite old 40 years ago.

I think hypothetically if there is a correct move/ the best move then all games will lead to the same.