It’s suggesting that line because white won the pawn and is ahead on material, and the extra pawn is weak (isolated D pawn). Trading the queens reduces the chances of black to generate counterplay as compensation for the lost pawn and reduces chances for black to win the pawn back. General rule, when up material trade, when down material avoid trades.
-Jordan
Thanks very much Jordan, that makes sense and is very helpful.
- Murray
When ahead material exchange pieces not pawns. When behind in material trade pawns not pieces...
https://chessimprover.com/the-art-of-the-trade/
check the section 'Strategy'...
https://en.wikipedia.org/wiki/Exchange_(chess)#:~:text=In%20chess%2C%20an%20exchange%20or,can%20capture%20an%20opponent%27s%20piece.
Lots of helpful, instructive resources in my blog...
https://www.chess.com/blog/RussBell
This is exercise 4 from chapter 5 of Patrick Wolff's book Learn to Play Chess Like a Boss. My question to follow:
Exercise 4: It's White's turn. Does either 1.Nfxd4 or 1 Nbxb4 win a pawn? Does Qxd4 win a pawn?
Answer: Yes Both moves win a pawn. White attacks the pawn on d4 three times, and black defends it only twice, so he (sic) can capture it. The game might continue : 1.Nfxd4 Nxd4 2.Qxd4 Qxd4 3.Nxd4, and White has won a pawn. 1.Qxd4??, however, is a very bad move because it loses the queen after 1...Nxd4.
My question: I understand the general answer that yes, White wins the pawn in the this exchange. And I agree that 1.Qxd4 is a bad move for White. What I would love some help with is understanding why after 1.Nfxd4 Nxd4 would White choose to capture the knight with their queen (as set out in Wolff's answer), when they still have another knight ready to jump into the fray? It is better to capture first using less valuable pieces, but perhaps there is an exception to this idea here that I am missing?
Any help much appreciated, thanks
Murray
(Brisbane Australia)