So I played the following game and made a blunder I don't fully understand.
The knight move is seen as a blunder (3 points towards opponent) while it's only result is the opponent taking a pawn, opening the line for my rooks. What's the problem?
Even I don't understand. We'll never understand Engines. Sigh.
It isn't a positional blunder but a tactical as Nh5 now for black wins material.
The real problem here is that after Nb5 there is Nh5 with an attack on the bishop and a discovered attack on the rook. When the knight was on c3 the bishop wasn't directly watching the rook, now that you moved it it has vision on the rook, so the discovered attack. Best move was either Rc1, going away of that diagonal, Bc2 so that you could have played Bd2 (with just Bd2 before Bc2 the Bishop on d3 would have been captured) after Nh5 or Qc2 defending the knight.
This is not a chess advice, I'm just a monkey that ate too many crayons.
I suppose that it makes me lose a pawn and initiative with is the reason for -3. The discovered attack is annoying but not too bad, it mostly seems to be all the things the opponent can do in their initiative which makes it bad.
#5
No black gains an exchange Bxa1 and also wins a piece Nxd3.
@tpr No they do not since Rc1, as demonstrated in the game.
#7
No:
12...c6 13 dxc6 Nh5 14 Be3 Bxa1 15 Qxa1 Nxd3 black is up a rook for a pawn hence -3.6
Nbd4 is more logical and also the best move indicated by Stockfish.
If only best moves are played:
12...c6 13.Nbd4 cxd5 14. exd5 Nxd5 15. cxd5 Bxd3 16 .Re1
This results in one pawn loss. That's it.
@SynapticSentinel tpr is right instead of taking the e4 pawn black has NH5 winning material. It's may be not such a trivial win for black from that position but that point is NB5 cost more than a pawn. even the c6 line given by stockfish cost you two pans in the end.
for me the positional "blunder" is rather to open the diagonal by moving your pawn forward on d5 and making lot of holes.
