Chess will never be solved, here's why

I'm thinking Na1 must be a very rare move.
Especially early in a game.
But when I looked up rarest move it wasn't there.

I really wanna correct everything you just said but I refrain myself

Moral of the story :you also have problems not just optimissed and not just everyone else

Cough denial in your post cough cough

@12208

"The computing power required is too much"
++ Required are 10^17 positions.
The 17 ICCF WC finalists looked at 90*10^6*2*17*3600*24*365.25*2 = 1.9*10^17 positions.

'easier to prune'.
Uh oh.

@12205

"e3 protects the critical diagonal that leads from b6 and c5 into f2 and g1."
++ But blocks the diagonal of Bc1 and controls only 1 central square d4,
while 1 e4 controls 3 central squares: e4, d5, e5.

'From the outset two moves, 1.e4 or 1.d4, open up lines for the Queen and a Bishop.
Therefore, theoretically one of these two moves must be the best,
as no other first move accomplishes so much.' - Capablanca

AlphaZero corroborated this in 4 training seeds of 1,000,000 games each with no other human input but the Laws of Chess: see Figure 31

The same scientific paper also ranks black defenses to 1 e4: Figure 30,
white continuations after 1 e4 e6: Figure 29,
white continuations after 1 e4 c6 2 d4 d5 3 e5 Bf5: Figure 28,
black defenses after 1 e4 e5 2 Nf3 Nc6 3 Bb5 a6 4 Ba4: Figure 27, and
black defenses after 1 e4 e5 2 Nf3 Nc6 3 Bb5: Figure 26.
All of that confirms human rankings obtained over centuries.

E.g. after 1 e4 e5 2 Nf3 Nc6 white has 27 legal moves, not the 31 claimed.
The same position also occurs after 1 e4 Nc6 2 Nf3 e5, or 1 Nf3 Nc6 2 e4 e5.
Logic ranks the 27 legal moves.

1. 3 Bb5: denies control of Nc6 over central squares d4 and e5, prepares O-O
2. 3 Bc4: controls central square d5, prepares O-O
3. 3 Nc3: develops a knight into play, controls central squares e4 and d5
4. 3 d4: opens a diagonal for Bc1, controls central squares d4 and e5
5. 3 c3: prepares d4, but obstructs the natural developing square of Nb1
6. 3 d3: opens the diagonal of Bc1, but closes the diagonal of Bf1
7. 3 b3: prepares finachetto Bb2 of Bc1
8. 3 g3: prepares fianchetto Bg2 of Bf1
9. 3 a3: denies ...Bb4 or ...Nb4
10. 3 h3: denies ...Bg4 or ...Ng4, but weakens the king's side
11. 3 a4: weakens b4
12. 3 c4: weakens d4 and b4
13. 3 h4: weakens g4
14. 3 g4: weakens the king's side
15. 3 Na3: cannot be better than 3 Nc3
16. 3 Be2: cannot be better than 3 Bb5 or 3 Bc4
17. 3 Bd3: cannot be better than 3 Bb5 or 3 Bc4, blocks pawn d2
18. 3 Qe2: premature queen move, blocks diagonal of Bf1
19. 3 Rg1: forfeits O-O
20. 3 Ke2: puts the king in jeopardy
21. 3 Ng1: loses 2 tempi
22. 3 b4?: loses the pawn
23. 3 Nxe5?: loses the knight
24. 3 Nd4?: loses the knight
25. 3 Ng5?: loses the knight
26. 3 Nh4?: loses the knight
27. 3 Ba6?: loses the bishop

So logic prunes 27 legal moves down to 4.
'Chess is a very logical game' - Capablanca
'Chess is the art that expresses the science of logic' - Botvinnik

You don't know the difference between logic and heuristics. Botvinnik was neither a scientist nor a logician. He was a chess player (and also an electrical engineer, interestingly)

"Chess is easier to prune than checkers."

how LMFAO?

"3 Bb5: denies control of Nc6 over central squares d4 and e5, prepares O-O
3 Bc4: controls central square d5, prepares O-O
3 Nc3: develops a knight into play, controls central squares e4 and d5
3 d4: opens a diagonal for Bc1, controls central squares d4 and e5
3 c3: prepares d4, but obstructs the natural developing square of Nb1
3 d3: opens the diagonal of Bc1, but closes the diagonal of Bf1
3 b3: prepares finachetto Bb2 of Bc1
3 g3: prepares fianchetto Bg2 of Bf1
3 a3: denies ...Bb4 or ...Nb4
3 h3: denies ...Bg4 or ...Ng4, but weakens the king's side
3 a4: weakens b4
3 c4: weakens d4 and b4
3 h4: weakens g4
3 g4: weakens the king's side
3 Na3: cannot be better than 3 Nc3
3 Be2: cannot be better than 3 Bb5 or 3 Bc4
3 Bd3: cannot be better than 3 Bb5 or 3 Bc4, blocks pawn d2
3 Qe2: premature queen move, blocks diagonal of Bf1
3 Rg1: forfeits O-O
3 Ke2: puts the king in jeopardy
3 Ng1: loses 2 tempi
3 b4?: loses the pawn
3 Nxe5?: loses the knight
3 Nd4?: loses the knight
3 Ng5?: loses the knight
3 Nh4?: loses the knight
3 Ba6?: loses the bishop"

you dont know if any of those arent necessary sacrfices with a 5 move deep combination.

and you already used vastly more computing power than one node per position.

Because it's a board game between two people, and or bots, etc.

Yes, 'electrical' meant literally electrical. Power grids, substations, three phase supplies, that sort of stuff. That being said, it is worth remarking that Botvinnik was very interested in the possibility of chess computers at a time when they were scarcely feasible. Turing and Champernowne wrote the first computer chess program in 1948, the year that Botvinnik became world chess champion. A few years later Botvinnik got interested in them. But he was also interested in the possible application of AI for the benefit of the Soviet economy! Way ahead of the curve (and all practical technology in both cases - even Turing's early program was too complex to run on any computer of the era. And AI has taken a while to meet the hype).

I suspect you mean @tygxc. I will reverse his downvote on your post that had content other than an insult.

I would suggest being more precise than calling him a moron, which is both vague and might be viewed as an infringement of forum rules.

@12228

Botvinnik held a PhD in engineering and worked from 1954 on a chess program Pioneer.
In 1968 he wrote Computer Chess and Long-Range Planning, in 1970 released by Springer-Verlag, New York. He considered chess as a generalised trade of material and positional values.
That is why 1 e4 e5 2 Ba6? can be dismissed right away, without needing a game tree.
White loses material and gains nothing in return, hence white loses.

As I said, it's a board game.

@tygxc, you refer to pruning one branch based on a human evaluation by a weak chess player. This is of course of very little help to solving chess since there are quadrillions (underestimate) of positions that have never been seen before and are of a similar ilk. You wish to prune all of these.

Clearly you must be relying on a computer evaluation of these positions. It would be very bizarre if you were to suggest that you are going to treat positions with the same evaluation differently depending on other factors - I think you accept you are not as good at chess as Stockfish - so we can assume that what you are suggesting is to ignore all positions with an evaluation less than a certain level. i.e. to assume that a -3 zero ply evaluation is ALWAYS a loss.

There's the problem. That is definitely false. There are undoubtedly billions (underestimate) of positions with a zero ply evaluation like that of a blundered piece that are not lost. We very rarely see just how bad a zero play evaluation is, but everyone has seen examples of Stockfish getting the wrong evaluation of difficult positions after already searching millions of nodes to tens of ply!

So now that you know that your approach is definitely invalid, @tygxc, what are you going to do about it?

@12229

"Inductive reasoning / intuition does not eliminate 10^__ # of positions."
Perfect alpha-Beta pruning reduces the number of positions to the square root.
Imperfect alpha-beta pruning somewhat less: exponent 0.67 for checkers.
That is indeed a reduction from 10^34 to 10^17, i.e. a reduction of 10^17.
For example these are 2 legal and sensible positions, both can result from optimal play by both sides, but a weak solution to chess needs only one, not 2.

Excluding the first position also excludes all positions with a black pawn on e7.
Excluding the second position excludes all positions with a black pawn on c7.
All positions with a white pawn on e2 are no longer accessible either.

There are 10^44 legal positions, but only 10^38 without underpromotions to pieces not previously captured. That is 10^6 reduction while nobody promotes to a 3rd bishop, rook, or knight in a perfect game.

Of the 10^38 only 10^34 to 10^32 can result from optimal play by both sides.
That is a reduction of 10^4 to 10^6.
It excludes positions like this one:

It is a legal position and it does not contain underpromotions to pieces not previously captured, but cannot result from optimal play by both sides. Convince yourself and try to come up with a proof game with reasonable play. You do not even have to prove it is optimal play.

Now explain how you are going to deal with the fact that your method does not work, as explained in my last post.

@12242

"pruning one branch based on a human evaluation by a weak chess player"
++ ICCF World Championship Finalists are no weak chess players, especially if they have average 5 days per move and use computers.

"you must be relying on a computer evaluation of these positions"
++ No. The ICCF WC finalists rely on their chess culture and test ideas with their engines.

"positions with a zero ply evaluation like that of a blundered piece that are not lost"
++ There is a difference between losing and sacrificing material.
Losing material is trading material for nothing in return and loses the game.
Sacrificing material is trading material in return for some kind of positional advantage.
The sacrifice may or may not be correct and the way to decide is to calculate.
However 1 e4 e5 2 Ba6? is loss of material for no return and is losing the game, not a single ply of calculation needed and not even an ICCF (grand)master needed, nor 5 days needed.
It is obvious.

"Stockfish getting the wrong evaluation of difficult positions"
++ All Stockfish evaluations are wrong: there are only 3 possible objective, absolute evaluations: win/draw/loss. All those +0.33 etc. are approximations.
However, the objective, absolute evaluation of 1 e4 e5 2 Ba6? is a black win.

Also, 1 e4 has a higher evaluation than 1 a4, regardless of engine, engine tuning, or thinking time. However, by pure logic it is unthinkable that 1 e4 would be a draw and 1 a4 would be a win. That does not need 1 ply of calculation, only logic.

@12245

"it should take a strong player less than a day to produce an example game"
++ I have played many tournaments. Once in a while the arbiter has to intervene to supply a second queen when a player wants to queen a pawn and his queen has not yet been captured. Luxury chess sets have spare queens for that.
Sometimes underpromotions to knights happen, because of the unique properties of the knight, but when that happens, at least one knight is generally captured. I never saw an arbiter intervene to supply a 3rd knight.

Underpromotions to rook or even bishop happen but only to avoid stalemate, i.e. only by the winning side. Even in the rare cases where these happen usually at least one rook/bishop is already captured. I never saw an arbiter intervene to supply a 3rd rook or bishop.

Apart from that, the vast majority of the 10^44 legal positions has multiple underpromotions from both sides.
https://github.com/tromp/ChessPositionRanking 
First position: 7 white rooks, 3 black bishops
Second position: 4 white rooks, 3 black bishops
Third position: 4 white rooks, 3 black rooks

Those 3 randomly sampled positions thus can never result from optimal play by both sides: it makes no sense for both sides to avoid drawing by stalemate by underpromotion to R/B.

"you need to promote with check, for example" ++ The only example I know is the Lasker trap, but it results from non-optimal play by both sides.
1 d4 d5 2 c4 e5? 3 dxe5 d4 4 e3? Bb4+ 5 Bd2 exd3 6 Bxb4 exf2+ 7 Ke2 fxg1=N+

@12249

"Some 0.00 positions are decisive, and some positions with high evals are draws."
++ That is what I say the whole time. The provisional, heuristic engine evaluations like +0.33 play no role, only the final objective evaluation win/draw/loss reaching the 7-men endgame table base, or a prior 3-fold repetition, or a known drawn endgame as judged that the two ICCF World Championship Finalists after days/weeks/months of consideration.

"why engines can be trusted" ++ On the contrary: engine evaluations cannot be trusted unless they reach the 7-men endgame table base or a prior 3-fold repetition.
The way to play ICCF correspondence is exactly to aim for positions engines misjudge.