Mate in 4 against Stockfish level 6?

It's relatively simple.
Stockfish on lower levels are programmed to make mistakes. The higher the level, the less bad moves it plays in a game.
If you play Stockfish on level 6, it statistically makes 1-3 inaccuracys in the first 10-15 moves and by some relatively low percentage 1-2 blunders.

If you play for example the same 5 opening moves 100 times, chances are high, that in 1 or 2 games Stockfish blunders something very early.

Its just simple statistics. I showed that some time ago with a scolars mate on a lower level of Stockfish...

lichess.org/forum/game-analysis/i-won-against-the-computer-level-2-twice?page=3#24

Notice, that I played it anonymously in a correspondence-mode, so I could easily abort the game, if the comp didn't fell for the trap... I guess I tried it about 30 times, before it worked.

Edit: I just watched the game history of that person with the "impressive" easy mate in 4: I stopped counting after Stockfish was in lead of 30 wins by 2 losses...

Have fun!

@borninthesixties said in #3:
> How come it never plays like that against me? I can beat level 5 most of the time but don't think I've ever won against level 6.

I normally just try to play solid until the middlegame, then SF6 normally blunders something sooner or later and I win.

If I miss the blunder or the inaccuracys it plays until move 30, then I often lose the game. Currently it's about 60/40 in my favour.

For comparison: I'm about 1500-1600 ELO (not Lichess rating).

Have fun!