I believe the answer is potentially. The main things which matter in high-level correspondence chess are:
Although I don't think either of those are really relevant. The really relevant bit is (apparently) planning:
For me, the key is planning, which computers do not do well — Petrosian-like evaluations of where pieces belong, what exchanges are needed, and what move orders are most precise within the long-term plan.
(From this interview with Jon Edwards (reigning correspondence world champion) from New In Chess)
I would highly recommend the interview on Perpetual Chess podcast also with Jon Edwards which I would also recommend.
I'll leave you with this final quote, which has stuck with me for ages:
The most important game in the Final was my game against Osipov. I really hoped to win in order to extend my razor-thin lead, and the game’s 119 moves testify to my determination. In one middlegame sequence, to make progress, I had to find a way to force him to advance his b-pawn one square, all while avoiding the 50-move rule. I accomplished the feat in 38 moves, in a sequence that no computer would consider or find. Such is the joy of high-level correspondence chess. Sadly, I did not subsequently find a win. But happily, I won the Final without it!
Interesting. Note that Jon Edwards didn't win a single game there via play - he won one game because the opponent inputted the wrong move, and another because the opponent quit the tournament. All other games were draws.
Yes, humans still provide value. Correspondence chess players will for example read chess opening books to find if there any mistakes in that book and even if they find just one, they'll try to lead their opponent into that dubious line, which is often a mistake that computers can't easily spot. Also as a former highly-ranked chess player, I'd use multiple chess engines at the same time to compare and contrast and also I'd know their strengths and weaknesses and which possibilities to explore.
Time should also be a factor when comparing strength between AI alone and an AI-human team. Humans might add to correspondence chess but it will cost them a significant amount of time. Human-AI teams are very slow compared to AI alone.
For example in low latency algorithmic stock trading reaction times are below 10ms. Human reaction time is 250ms. A human-AI cooperation of stock traders would have a minimum reaction time of 250ms (if the human immediatly agrees when the AI suggests a trade), This is way to slow and means a serious competitive disadvantage.&...
Presumably you could test this directly. Have 100 players play a correspondence game against each of the top 3 chess engines, where you gave them a max amount of compute time they could use (say no more than 2 hours per move) and they just play directly against the computer.
My guess is they would have a slight advantage, at least over stockfish, if only by exploiting known bugs/adversarial situations.
FWIW, the two main online chess sites forbid the use of engines in correspondence games. But both do allow the use of opening databases.
(https://www.chess.com/terms/correspondence-chess#problems, https://lichess.org/faq#correspondence)
Do humans still have something to add? The continued existence of correspondence chess, IMO, suggests that they do.
Sorry, but that is absurd: the fact that humans continue to play correspondence chess is only the most teeniest tiniest evidence that humans have something to add.
I am interpreting, "humans have something to add," as "the best human player using computers still has some kind of advantage over a computer alone where no human is allowed to intervene in the operation of the computer over the course of the game except perhaps to ensure a steady supply of electricity".
Note that I am not opining either way on your overall question. I am commenting only on what conclusions we can draw from the fact that people still play correspondence chess.
Why do you think so?
Presumably the people playing correspondence chess think that they are adding something, or they would just let the computer play alone. And it’s not a hard thing to check; they can just play against a computer and see. So it would surprise me if they were all wrong about this.
Human social behavior is complex. Maybe some or all of the winners of ICCF tournaments won by merely parroting the moves chosen by an engine, but they chose not to admit it out of a worry that admitting it would cause a change in the rules that would disadvantage them in future tournaments.
A document titled "2023 ICCF Rules" does not exactly explicitly encourage the parroting behavior I just described (though it does not explicitly disallow it either):
In ICCF event games, players must decide their own moves. Players are permitted to consult prior to those decisions with any publicly available source of information including chess engines (computer programs), books, DVDs, game archive databases, endgame tablebases, etc. . . . No other consultation with another person concerning analysis of an active position is allowed . . .
The only things I omitted from the paragraph I just quoted have to do with humans playing as a team.
I have quoted from the public written rules of the tournaments because public written information is all I have access to. Communities often develop unwritten rules that strongly influence human behavior -- rules we would have no way of knowing about without asking a community member in a context in which the member has some basis for trusting us.
It might be the case that ICCF's leaders see it (correctly IMO) as impossible to enforce a rule against chess engines, so they allow them as a practical measure, but they don't like them, and most of the winners know that, which again would tend to cause anyone who won by merely parroting moves chosen by an engine to choose not to announce that fact.
Or it might be that the majority of those with a megaphone that reaches the correspondence-chess community maintain that chess engines have ruined the once noble and delightful correspondence-chess scene, with again the same effect.
If the organizers of a tournament explicitly declared that one of the purposes of the tournament is to determine whether human-computer teams can outperform computers alone, then that would start to be evidence worth considering (against, e.g., the evidence provided by the overwhelming dominance of computers over human-computer teams in chess with other rules (other time controls to be specific) -- particularly if there was decent prize money.
In chess, AIs are very superhuman; the best players in the world would lose nearly every game against any modern computer player.
Do humans still have something to add? The continued existence of correspondence chess, IMO, suggests that they do. In correspondence chess players have days to make each move, and play from their homes. Due to the impossibility of policing cheating under these conditions, correspondence players are allowed to use computer assistance.
You might think this would make the games just a question of who has more computing power. But as far as I can tell, that’s not the case.
What are humans adding? Low confidence, but I think it’s mostly opening prep; try to find a line that looks ok on shallow computer analysis, but where deeper analysis shows you have an advantage. The human value-add is telling the computer which lines to analyze. Since the chess game tree is so large, advice like this is quite valuable.
Proof that correspondence chess is still played: https://www.nytimes.com/2022/11/09/crosswords/correspondence-chess.html Interview with a human player (from 2016): https://en.chessbase.com/post/better-than-an-engine-leonardo-ljubicic-1-2
On the other hand: I don’t play correspondence chess, so I’m not that confident in the claims above. And some people don’t find them plausible: https://twitter.com/liron/status/1660890927920201728?s=46&t=UlLg1ou4o7odVYEppVUWoQ
Why should we care? This might provide some indication of what value humans can provide in a world of superhuman AI (at least initially).
Can anyone provide a more definitive account of what value, if any, humans add in correspondence chess?