Mate in 3 Stockfish can't solve

A very clever puzzle, literally giving moves to the opponent to ensure they won't stalemate.

StockFish can't solve it? Blah, blah, blah.

Yeah. Stockfish would find this in negative seconds

To be fair, the chess.com engine (which is apparently Stockfish 11 at some extremely shallow depth) settles for mate in 4.

Currently chess.com offers a choice of 3 engines, two of which are variants of SF15. All 3 solve it in a second provided the search depth is set at maximum value. And why not?

We had SF11 for a while during jan/feb 2023 possibly to fight overload problems on chess.com. Perhaps some devices or user accounts require reselecting one of the current engines.

For me, the options are: SF 11 or Komodo or "Engine off" (??).

Even more bizarrely, I switched to Komodo, and he solves it in 0.1 seconds; then I switched back to SF 11 and now even he solves it in roughly 1 second.

I have Komodo, SF15 NNUE and SF15 (faster) as I used to have halfway 2022. Unless I am privileged (though I have just a guest account) I can't explain the difference. Can somebody?

Generally it's a good idea to restart the computer. Never know what the engines keep in cache.

Fun puzzle.

It's called stonkfish

I solved it in like 15 tries. I suck.

It depends on the browser used. Chrome and MS Edge have SF15 (with/without NNUE). Firefox has SF11.

Thnx! For once I'm lucky. I suppose it's something technical. But there are other factors as well since I did lose my SF15s during a few months. Wonder if there is some sort of maintenance page that keeps track of those technical states and issues.