Why is B

When playing as Black(and sometimes White) why is the early trade of your white-squared bishop for a knight so often played? I do it because I see it often in master games, but I don't understand the advantage.

If you don't know what I mean, it usually looks something like this.

I see this very often where black will push for Bg4 on their Nf3 for an exchange. Can someone please explain why this is so often done? Is it just to break up their King's defense? Thanks

(Please no game advice as this is an active game)

hey,that is calles tromposky attack,is good cause you eat the Knight and put two pawns on the same line,that break allittle bit your opponent deffense and He s not gonna rook to that place,sorry mu english

called*

at that Game,It only eat the Knight,cause nobody are gonna eat with the pawn that protect your King so hes gonna eat with queen

Thanks!

Generally one doesnt trade the white squared bishop for knight without a purpose. The pin on the knight here is way more valuable than a pawn. Plus it is on the kingside so the only time to trade is if the G pawn takes the bishop other wise keep the bishop.. An idea that is followed by bg4 is nd4 as the queen is vulnerable as long as whites black squared bishop cant play to e2. Hope this helps.

Its considered cheating to ask about an ongoing game.

Question wasn't about the game more about the idea of swapping the white squared bishop of for a knight in games in general.