1 e4 c6 2 d4 d5 3 ed cd 4 c4 Nf6 5 Nf3 Bg4

This last bishop pin is not ever played by the grandmasters according to chessgames.com,

but i played it,

why is it bad?

Well, personally I can't find any dramatic reason why that couldn't be played. It seems quite OK to me. Perhaps with a larger database one could find high level games where the pin has been played in that position.

Of course it might be that since black can't really mount an effective quick attack against white's d-pawn, the white knight really wouldn't move from there anyway, and perhaps black might not want to trade his bishop for the knight and give away the two bishop advantage to his opponent. Of course, if white doesn't play Be2 soon, or add a protector to the d-pawn, after Nc6, black might be able to disrupt white's kingside pawn structure with the trade, so that might be a redeeming idea.

Or perhaps I'm just mising some brilliant tactical sequence by white that completely refutes this superficially OK looking move.... 🙄

-Jarno

There doesn't seem to be anything wrong with 5...Bg4. I found 31 games on my database, with Black doing ok. The reason it's not played very often is because White hardly ever plays 5.Nf3. In the vast majority of games, White chooses the natural 5.Nc3.

I found a lot of games where it s played a little later

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nf3 Nc6 6. Nc3 Bg4

( I found lines going as far as 14 moves. Have a look at this one :
1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nf3 Nc6 6. Nc3 Bg4 7. cxd5 Nxd5 8. Qb3 Bxf3 9. gxf3 e6 10. Qxb7 Nxd4 11. Bb5+ Nxb5 12. Qc6+ Ke7 13. Qxb5 Nxc3 14. bxc3 Qd5 )

So why is it better to develop the knights first ?
Maybe it s not a bad move, maybe Nc6 is just more popular.
Only reason i can see is black not taking the risk to lose a tempo
after h3. What would you play in answer to h3 ?

In most games white does not mind the pin,
the white queen goes to b3.
White does not even mind trading knight against bishop on g3,
and a bad pawn structure.
I found lines going as far as 14 moves. Have a look at this one :
1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nf3 Nc6 6. Nc3 Bg4 7. cxd5 Nxd5 8. Qb3 Bxf3 9. gxf3 e6 10. Qxb7 Nxd4 11. Bb5+ Nxb5 12. Qc6+ Ke7 13. Qxb5 Nxc3 14. bxc3 Qd5

I love these kind of questions. Start a game less and post more 😀

just a quick note for you is usualy marsters like to keep bishops for the end game unless there structure of the oponent is greatly reduced in the centre game . as bishops are more useful at attacking in open play knights are manoverable in locked possitoins as with rooks open play is there stength enjoy playing everyone