Lessons From Prague 5

IN round five with white I gained the bishop-pair and had the better pawn-structure, but Stockfish15.1 and Komodo14.1 reckon the following position is equal.

I have just played 17.c3

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Stockfish15.1 recommends 17...Nf6, claiming more-or-less complete equality, although Komodo14.1 is not so convinced.

The latter engine prefers 17...c5, although this time Stockfish15.1 doubts that the position is equal.

At any rate both moves are better than the 'clever' 17...Nc5?, which my opponent said afterwards he recognised as bad immediately on playing it.
The point is 18.Bxf5 wins a pawn, and although 18...gxf5 (the engines reckon this is better than 18...Nd7) 19.dxc5 cost me the bishop-pair and gave me a compromised queenside pawn-majority, White is very much on top.

LESSON: as with my round-four game, playing ...Nc5 is another example, albeit in a slightly different form, of 'automatic' thinking. White saw that immediately capturing the knight would not win a piece, and so assumed ...Nc5 did not lose material, but he missed Black's simple zwischenzug.