Is this the correct trade?

I just traded two bishops for a rook in a game I play. It was an accidental blunder to be honest as i mis-caculated thinking i could take the knight back. But generally speaking, I've come across similar situations before.

Is it a major blunder to trade a knight and bishop for a rook? I've come across that situation alot so is it a blunder or good/justifiable?

I know two bishops for a rook is probably not a good trade? Not sure on the knight and bishop for rook though.

Link to game although its just a general question rather then anything specifically to do with this game:

move 21

If two GMs are playing an end game, same number of pawns. One has one knight and bishop and the other has just a rook, who wins?

Thanks all

Two pieces for a rook generally is a bad trade. The point is that the two pieces can attack a pawn twice, while the rook can defend it only once.

Each combination of 2 pieces (NN, BN and BB) is more powerful than a rook, especially the bishop pair combination. This applies especially when you're attacking the King, 2 pieces are more troublesome for your opponent than just a rook. Also the post written by @tpr is a good reason to not give up 2 pieces for a rook. You can both defend and attack a square or piece twice when you have 2 pieces, but a rook by itself is not capable of that.

There's a generally accepted point system that the bishop is worth 3.25, the knight is worth 3.2, and the rook is worth 5, so basic math proves that neither trade is worthwhile. In the middlegame, the two pieces coordinate better than a rook could ever hope. In the endgame, the rook becomes more powerful and may, especially with an extra pawn, may hold the position.

What really confuses me is why didn't you capture the knight on move 23? Even if black's rook was unprotected, and you thought that the pin would win the piece, the knight can retreat and protect the rook.

@jonesmh good point... I did see that and I had a think but I think my calculations screwed up (blunder) which is why i didn't take the piece... Silly me.

Why didnt you take the d5 pawn on move 8?

@paradoxial a knight for a pawn? Or am I mis-calculating a combination with that pawn take?

Potentially two pawns for one knight? Knight takes E5, Pawn takes knight on E5 then bishop takes pawn on E5? Is that the combination?

Two pawns for a knight seems like a slight blunder unless its worth it for centre position? (I'm still relatively new so could be missing something)

@bruce_wayne1 his pawn is pinned, so you gain a pawn, therefore he'll have to compensate by taking your f pawn. You'll end up with the same material but I'm sure white has a small advantage as he'll be more developed

@paradoxial, good spot, totally missed the pawn was pinned... a blunder by me.

@bruce_wayne1 no not a blunder, just gives a small advantage, your alternative was perfectly fine