Why is 8. Qd2 a mistake?

Stockfish is showing if you are going to move the queen, play Qe2. However, if you follow the moves out, it then goes to d2.

8.Qe2 e5 9.h3 exd4 10.Nxd4 c5 11.Nf3 Nh7 12.Qd2 b6 13.Nc3 Bb7 14.Bc2 Re8 15.Qxd6 Bxc3

Isn't that a waste of a move? I miss how that is a mistake to put it on d2 to begin with.

I got some stupid link restriction, "You have reached the daily maximum for links in forum posts."

So just remove the * symbols to get to the game. (Lichess, WHY? Why are you limiting us from linking to an area on your site? It makes no sense.)

h*t*t*p*s*:*/*/*l*i*c*h*e*s*s*.*o*r*g*/*s*t*u*d*y*/*f*v*o*A*V*l*Y*O*/*m*L*A*D*J*v*V*w*#*1*4

And here are the moves.

1. e4 d6 2. d4 Nf6 3. Bd3 g6 4. c4 Bg7 5. Be3 O-O 6. Nf3 h5 7. O-O Nbd7 8. Qd2 Nb6 9. Bh6 e5 10. Bxg7 Kxg7 11. dxe5 dxe5 12. Nxe5 h4 13. h3 Bxh3 14. gxh3 Re8 15. Nf3 Qd7 16. c5 Na4 17. b3 Nxc5 18. Rd1 Qxh3 19. Qf4 Red8 20. Nc3 Rxd3 21. Rxd3 Nxd3 22. Qe3 Qg4+ 23. Kf1 Nf4 24. e5 Qg2+ 25. Ke1 Qh1+ 26. Kd2 Qxa1 27. exf6+ Kxf6 28. Qe5# 1-0

It says it on the next move's analysis; Ng4 attacks the dark bishop, and you've just cut off its retreat. It can only advance into pawn attacks, and die. Black has built their board to maximize the power of the dark square bishop; you really want to hold on to yours. That's why the engine likes h3, it stops the knight from getting to g4.

@dnowmects said in #2:
> Black has built their board to maximize the power of the dark square bishop; you really want to hold on to yours.

Thank you for commenting. The plan was to trade it off. Not a good idea?

There are only a few positions where you want to trade your bishop for your opponent's knight. Usually it's in order to immediately control a square that only their knight could cover, which isn't happening here. Bishops are generally stronger than knights until the endgame, and in a position like this where Black has fianchettoed their bishop, put their king behind it, and built their pawn structure around it, that bishop is often worth more than a rook. Trading their knight for the bishop you could use to challenge their doom bishop is solidly in their favor.

@dnowmects said in #4:
> There are only a few positions where you want to trade your bishop for your opponent's knight. Usually it's in order to immediately control a square that only their knight could cover, which isn't happening here. Bishops are generally stronger than knights until the endgame, and in a position like this where Black has fianchettoed their bishop, put their king behind it, and built their pawn structure around it, that bishop is often worth more than a rook. Trading their knight for the bishop you could use to challenge their doom bishop is solidly in their favor.

No, I am talking about trading my DSB for their DSB: Qd2, Bh6, Bxh6, and Qxh6 or Qd2, Bh6, black move, Bxg7, Kxg7.

Ng4 guards h6 too. There's no bishop trade, it's still the knight.

Ok, I see. Even if you play h3, Qd2 later still looks bad according to Stockfish because black's queen's knight can jump into the center and with Re8 there is an attack on the e pawn after black's e pawn gets traded. I'll have to look more into this later. Thanks for walking me through this.

Apparently he walked you right out the door!