I have only recently started correspondence chess and I have read that engines are allowed in correspondence chess. I definitely do know that the world champions of correspondence chess have said that using engines to a 100% degree is a bad idea. My question is this: What is the most efficient way to use engines in this format of chess? Any experiences would be helpful!

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    Word of caution: engines are allowed in the ICCF (International Correspondence Chess Federation). Engines are by default not allowed in "correspondence chess" on sites like lichess.org and chess.com. Read the rules of the organisation you are playing with before starting.
    – Remellion
    Jan 22, 2020 at 5:58
  • @Remellion Excellent comment. Jan 22, 2020 at 10:15
  • What is an example of an organization that allows engines? I skimmed the linked article but didn't find it. Jan 22, 2020 at 12:21
  • @Remellion quote and source for that ICCF rule. There is no way to tell or police computer use and they have been used ever since Hans Berliner won the world championship using some at IBM. Jan 22, 2020 at 15:38
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    I found ICCF rules here iccfwebfiles.blob.core.windows.net/rules/2020/… "In ICCF event games, players must decide their own moves. Players are allowed 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." that etc on the end make the rule a bit unclear, but it clearly includes engines. Jan 22, 2020 at 19:57

2 Answers 2


Obviously, as long as they are permitted within the rules of the organization, here is how I would use a computer.

First, realize that different programs are better at different things, and I will divide them into two categories. I heard GMs Peter Svidler and Jan Gustafsson discuss this during the Firouzja-Carlsen game just yesterday.

The first program is for opening play, and that is where Leela shines. I have not had much experience with this program, but Jan mentioned that it can, apparently, blunder at times. They both agreed that Stockfish is still the king of analyzing in the middlegame. I watch a lot of relays of top tournaments, and I follow along with Stockfish, and it is currently the best program out there for the middlegame, and the best part is that it is free.

The next thing is that in most circumstances, I only look at the top two lines (in ChessBase, you can click the little plus/minus sign in the engine box to add/remove the number of lines). I would probably increase this to the top 5 lines for correspondence since there may be a line that fits in better with what you are trying to do, so you can, at least, know to explore it.

Next, in the opening, it helps if you have a good understanding of the opening pawn structure, and the typical plans that are played. As you get into the opening, look at a bunch of GM games from a database to see what they have done before you decide on your moves. Have Stockfish going while looking at them...you never know what you might find if it pops up an unusual eval.

Lastly, and the stronger you are, the easier this is, and the better you will be at it, but you want to play "advanced chess". "Advanced chess" is term for using both the computer and your knowledge to pick the best move. In its infancy, Anand was considered the best at this, and there were a few tournaments where these top players were allowed to use a computer. Here is an article. As part of this cyborg play, and this is the key, you want to force in certain series of the computer's best moves or even some of your own human moves, so, in essence, the program only starts analyzing from that point.

For example, if you and I are playing and we are on move 28, and you just let your computer analyze from there, it may analyze out to move 38. Not bad, but if I am able to force in 7 likely moves based on my 40 years' of experience and the computer's evaluation along the way, and only then let it think uninterrupted, I start at move 35, and might get to move 45.

If you are evaluating a position based on the end result at move 38, but I am evaluating it based on move 45, 7 moves later; I am much more likely to be successful, and win the game.

That is how I would use one if I played correspondence chess. Frankly, I am too impatient so I was never into correspondence in the old days of postcards, but the advent of computers really turned it into more machine versus machine, so that really killed any chance I would get into this in the future; but to each his own.

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    I haven't played this way, but it seems like these days whoever knows how to tune their engine and has the most / correct kind of compute power would win. I can't find the exact quote right now but I recall that Magnus said about computer play that they play like they don't understand anything and then they win. If computers win by playing weird moves then how am I to judge these moves? Jan 22, 2020 at 12:32
  • I would be interested in a match between a grandmaster with a computer vs just the computer with the same specs. I'm not convinced the grandmaster actually adds any strength in the long run.
    – orlp
    Jan 22, 2020 at 14:50
  • I've talked to a few correspondence players on the leela discord who say it's pretty obvious when someone is just letting an engine play for them. Turns out the engines are fallible in ways that are sometimes easier to see than to fix. Jan 22, 2020 at 22:15

This is by no means complete, but here's a few things.

  1. Use at least 2 engines. More different is generally better. Lc0 and SF would be an obvious pair.
  2. Especially with leela, look at the point of view of the engine. Dig into disagreements.
  3. Realize most of your games will be draws
  4. Make sure you have tuned your engines for long time control. For leela, that typically means using a bigger net since you will have plenty of time to get nodes.
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    I contribute with this idea: Look for positions in which several good moves looks almost the same to an engine. Its like a flat landscape. Or on the contrary, look for very complex positions that the horizon is far deep that your opponent will burnt his machine, before finishing on time his analisis.
    – djnavas
    Jan 23, 2020 at 10:10

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