SuperComputer Chess Problem

One of the hardest ones I've ever seen. Even stockfish has trouble with it. Good luck lol

amazing

This is an old well known mate in 13 that stumps most engines, the specialty engines that specialize in chess problems and mates like Crystal, Stockfish matefinder, and Fat Titz 2
solve this easily, but Stockfish, Komodo, and others that are designed to play a strong game struggle with it.

How do mate finders/crystal work that allows them to beat the horizon problem that normal engines have?

They use tricks like less pruning and/or disabling Null move pruning.

Ah, that's nice! I discovered/invented "Null move pruning" decades ago as a powerful analysis tool for chess and now I read it actually exists - not just in my mind. It's related to the "series-mover" with ideas like "if you can't win "easily" if you play 2 or 3 white moves in a row then are probabliy not in a winning position". With my other discovery of the Monte Carlo method I could have started a chess software company in those days. Well - if I had the drive to go there and the training to convert my concepts into concrete algorithms. I hated to get my hands dirty.

For the sake of being extremely precise, the problem a "common" engine has, is not the "horizon effect". Horizon effect is a different thing, and refers to the fact that every engine has a maximum depth at which it can search. Anything that is beyond such depth, is somehow called to be "behind the horizon" and therefore invisible to them. This is apparent if you leave an engine to search for an indefinite time: you will see that a given depth is reached, but not beyond that. This is the horizon effect. What you're referring to, is the engine's inaccurate selection of the proper candidate move (in the PV) that causes it to not find the Mate. As others explained, the reason for the failure is that a "common" engine uses a number of algorithms to prune the branches that are *likely* safe to prune (like the mentioned null moves). Engines that are specialized as mate finders, use way less of such algorithms. They are therefore capable of going much less deep with the calculation, but much more accurate. Nowadays' engines are "smart" enough, on most occasions, to know when it is better to employ or not a pruning algorithm. But not always, hence their failure in finding the Mate in some occasions.

It would be interesting to design an engine that could "understand" these problems in some AI sense.

They will! But don't be surprised if solving a 2-mover will then take a week; 1 microsecond for the moves and the rest to mine the worlds databases to find proper context and understanding of the themes

And a fun note - BUT TRUE - on AI. A week ago a report was released by AI-experts on self-driving cars (like cabs) in Amsterdam. It advised against allowing those since safe driving in A'dam requires breaking the traffic rules and the Robo-cars couldn't do that. Which is to say they probably couldn't learn when, why and how to break the rules with the refined judgement of human drivers!

Here's another interesting one, it's a mate in 6, but there are several winning paths that I think fool engines that heavily prune the search tree, but not the specialty engines:

It should also be noted that Stockfish 14.1 solves this puzzle in 1 minute 38 seconds on my computer:

Maybe it's a hash size issue. Larger calculation horizon if the solid state drive / RAM size is larger, can accommodate mote calculations, making it more likely for the solution to fall within the horizon. I still can't figure out how to get stockfish for a windows laptop.

You can easily get Stockfish for a windows laptop, unless the laptop is 32 bit, but even then you can get older versions for 32 bit.

No its 64 bit, but can't find where to download it or how to activate it.

try here ----> https://stockfishchess.org

I think that's what I tried on my old laptop, it just downloaded some non-executable file. Haven't tried on my new one yet, will see.

Just tried it on my new laptop, won't work. It just says extracting files and then that's it, nothing happens. The command prompt opened, that's it. What is going on??

Do you have a GUI to run it in? Like Arena, Lucaschess, Tarrasch, or even Fritz/Chessbase?

Remember when you download the engine you need an interface to run it in otherwise you would have to run it from the command line. I use Arena GUI 3.5.1 which you can download from the link and it is free, I recommend getting the "setup version"
, after you have installed Arena and have EXTRACTED Stockfish 16 from the zip file you that downloaded, then you are ready to "install" the engine to Arena
, so you would go to the "engines" menu in Arena and choose "install new engine" and then find the Stockfish executible where you extracted it to and then select the executable
, then Arena will ask you if you want to "start Stockfish 16" which you will answer yes
Now Stockfish 16 will be loaded and ready to go, and you will be able to copy and paste FENs and PGNs into the GUI and then have Stockfish 16 run in infinite analysis mode.

Think i got it, thanks!