Chess will never be solved, here's why

@5453
""solve" means something entirely different"
++ No, I adhere strictly to van den Herik:
'the game-theoretic value of a game is the outcome when all participants play optimally'
'weakly solved means that for the initial position a strategy has been determined to achieve the game-theoretic value against any opposition'
'optimal means most desirable or satisfactory' - Webster
'oppose means to strive against, resist' - Webster

1 e4 e5 2 Ba6? is not optimal play and does not oppose to the game-theoretic value.
1 e4, 1 d4, 1 c4, 1 Nf3 are more optimal and resist more to the draw than the other 16.

All those familiar with the peer-reviewed literature understand that "any opposition" means any legal opposition. You use an inappropriate, woefully vague (i.e. undefined and undefinable) alternative.

@5453
""any opposition" means any legal opposition"
++ Where in any peer reviewed literature is said that 'any opposition' means 'all legal moves'?
If they meant that, then they would have written 'all legal moves' and not 'all opposition'.
Also the van den Herik paper clearly calls for all participants (white too) to play optimally.
There is nothing inappropriate, vague, undefined, or undefinable in that.
White tries to win, i.e. oppose to the game-theoretic value.
Black tries to draw, i.e. achieve the game-theoretic value.
If white fails and black succeeds, then Chess is weakly solved.
1 e4 e5 2 Ba6? or 1 a4 do not even try to win.
These are neither optimal nor oppose to the game-theoretic value.

All published solutions of games involve using this definition and not some half-cocked one based on only showing you can beat moves that imprecise heuristics suggest are better. For example, no-one claimed checkers had been solved until the job had been done properly. That means strategies that are proven against all legal opposition.

Here is a quote from the peer-reviewed paper announcing the solution of checkers after many years of exhaustive computation:

"The proof consists of an explicit strategy that never loses – the program can achieve at least a draw against any opponent, playing either the black or white pieces."

The italics are from the paper, and emphasise that a strategy has to be proven against any strategy ("opponent"). Given a position and a legal move, it is easy to define an opponent/strategy that plays that move. Thus my point is confirmed.

Checkers is solved (Science, 2007)

@5449
Now you invent a new meaning of the van den Herik paper.
Solved games like Checkers, Losing Chess, Nine Men's Morris, Connect Four are simpler than Chess. All of those games have a high fraction of irreversible moves.
Chess has an enormous number of nonsense moves.
There are billions of ways to reach the position 1 e4 e5. All but one are nonsense and irrelevant to solving chess.
That is why for weakly solving chess it is not only allowed and beneficial to incorporate knowledge, it is a necessity. That is also why GM Sveshnikov called for good assistants first and for modern computers second. One cannot do it without the other.

No new meanings, just (to be frank) superior understanding.

The word "any" in the paper is unambiguous.

Firstly, it is not "opposition", it is "opponent".

Secondly, "any opponent" (with the italic used in the paper) is unambiguous. It is not some vague subset of them, but ALL of them.

When a GM turns up to a simultaneous display against 100 players aiming to get a 100% score, he doesn't start by saying "I'll take all the wins against players of rating less than 1200 as a given" and then proceed to play the rest. He doesn't get a win if he doesn't play.

Likewise a proof tree has to deal with weak opponent moves as well as strong moves in order to do its job.

@5461
But the word 'opposition' is unambiguous too, cf. Webster dictionary.
'Any' opposition means against 1 e4, 1 d4, 1 c4, and 1 Nf3. Not just one of those.
'All participants play optimally' is unambiguous too.

Relevant are:
How to draw against 1 e4?
How to draw against 1 d4?
How to draw against 1 c4?
How to draw against 1 Nf3?

Not relevant are:
How to win against 1 g4?
How to draw against 1 f3?
How to draw against 1 Na3?
How to draw against 1 h4?

The word "opponent" is the relevant one, since this is the word used in the paper. "any opponent".

Every single person with passable understanding of the subject understands the meaning.

@5466
"The word "opponent" is the relevant one" ++ in a paper about Checkers only.

The van den Herik paper is more relevant: 'Games solved Now and in the future'
'All participants play optimally'
'any opposition' not any legal moves

Hope GM Niemann doesn't read that - you might give him ideas

The phrase, "all participants play optimally" is used only to define "game-theoretical value". There is nothing in van den Herik's paper that says the phrase can be applied in any context tygxc pleases.

Of course not "any legal moves".

This is a frustrated win under competition rules.

White to play

White can win against any legal moves but he can't win against any legal moves and draw claims. Legal opposition includes both. It definitely doesn't say, "weakly solved means that for the initial position a strategy has been determined to achieve the game-theoretic value against anything tygxc would play"; I've read it.

The definition you're using is in any case flawed as I've pointed out many times before. 

The strategy "play Qa7" from the position below is a strategy that achieves the game theoretic value of a Black win against all opposition (in an abstract game that doesn't include resignation; in the FIDE defined games there can be no game theoretic value). That accords with a weak solution of the position according to your definition, but is not what anybody on the thread except yourself would call a weak solution of the position.

White to play, ply count 0

Incidentally no show yet for your calculation of the theoretical result and error rates in my games here. Are you still working on it?

Will it take more than 5 years? Do you need a supercomputer before you can start?

You understand that people can see right through your constant claims of knowing what anyone/everyone else thinks, right?  That's part of your delusion...the idea that you are representative of others when you go out of your way to make it clear you are better than they are and don't give a hoot about them.

You have a few crackpots that talk to you, who are themselves persona non grata in general here and who also habitually try to be a nuisance, as you do.  Hardly a representative sample of anything worthwhile.  

No, crackpots consist of:

- Those who think they have psychic powers

- Those you argue against climate change using daffodils as a main argument

- Those who shoot airguns at paper cups in their garages, measuring themselves for accuracy and speed

- Those who pop in and out from the tropics in a manic fashion and declare things that make no sense

Etc.

The specific manifestations are quite varied, but the criteria is pretty much the same.

I've already contributed far more to this thread and others of its ilk than you ever will with your vague posturing and naysaying of basic definitions.  

Background noise is what your arguments amount to.  Feel free to peruse the thread and you will find all the concrete things you have forgotten .

If you did have better things to do you wouldn't be adding more of your "and another thing" consecutive posts .

Getting confused here. I thought we were talking about this paper.

1.1 Conventions  para.2 (p278.)

weakly solved means that for the initial position a strategy has been determined to achieve the game-theoretic value against any opposition,

@MARattigan, I wasn't and you will find the paper published in Science that I referred to linked from my earlier post:

Checkers is solved

That being said, the meaning of "any opposition" is the same. There is no unambiguous distinction between opposition that needs to be addressed and opposition that doesn't without properly verifying it.  Indeed "opposition that is not good enough" can only really be defined unambiguously by the result that it achieves, something which is not certain until it is checked.

The weak solution of checkers and every single other case of weak solution dealt with in the literature of course uses the same definition and is equally thorough in the way that it applies it. That is why the solution of checkers took years of computing.

EVERY single legal move by the opponent of a strategy needs to be checked to a known result (assisted by a tablebase).

     Who gets to judge what is/is not "stupid"? A panel of five GMs? AlphaZero? Optimissed? Once you arbitrarily omit broad swaths of lines from consideration, you open the conclusions reached to reasonable doubt.

It would be a big step forward if some people here would take the time to understand what was done in the weak solution of checkers and other games, and to realise that tells you what is necessary to solve chess (according to the universally accepted meaning). It's just a lot harder because of the size.