What went wrong?

I played this game and it looked like I was going to win after a blunder from my opponent. Somehow I screwed up and lost the game anyway. I really can't find where I made a big mistake so it might have been a bench of smaller mistakes that cost me the game.

Could any of you help me and figure out what went wrong?

Thanks in advance

19. g4 seems like a bad idea.

why? because I think it gives black counterplay (you might have to worry about Qd6)...your making your king vunrerable unecessarily

25. Qh1

this seems like a poor defense, seeing as Qh4 is not a major threat.  I prefer Rae1 or Rad1

26.Rae1 ...probably should have traded with Bxf5

27. Qxh7+ .... this is one of those moves that might be tactically justifiable, yet strategically speaking, a blunder.... If the Black rook ever goes to that open file, it could be game over very quickly.

28. Rf3.... probably lost the game outright

I think much better is Bd3.

...as for the rest of the game, it was lost already.

Well there can be many improvements for both sides. But I dislike your 25-Qh1 most.Though you later got to play Qxh7 still it was bad because 1-You left your weaknesses as it is 2-Queen is badly placed at corner. 3-you are not using Rook stranded at a1.

A simple 25-Rae1 solves all your problems. e3 gets support so you can move out Be4. Queen is less burdened now. As for covering h4 , it was not required at all.After 25- Rae1 Qh4  26-Re2 saves attack at h2 . I think you have a very promising game after Re1.

Thanks for the comments. I'm going to try and dig a little deeper into the positions when I have a bit of time. I hope I can improve my game a bit after this.

g4? Why?! You are opening up lines in front of your King without a hint of an attack to justify it. None of your pieces were active. I think the correct decision was to improve/activate your pieces, and open up some lines on the queenside --instead you did the exact opposite; you pushed a pawn that opened up lines on the Kingside!?

As so often happens after you win material... your position is temporarily worsened...  often it's that making the capture brought one of your pieces out of position, in the case of your game here you exchanged your hardest working piece, a very active N for his relatively passive Rook... yes, it's a winning advantage to bring to the endgame, but you aren't there yet... in effect, you've fired your gun, now it's time to reload -- you needed to regroup and get your other soldiers up to the front... not launch a completely unprepared for unsupported pawn thrust. g4 was positional suicide IMO, and kudos to your opponent for pouncing on it... after blundering badly he redeemed himself and played like a tiger.

Move 19 is a mistake as it unnessasarly opens up your already fianchetto'd kingside.  I have not analysed this in a computer, but this looks wrong based on technique.

Move 26. is a mistake.  You are up the exchange and need to simplify the position So BxN here as a knight on the 6th or 3rd Rank is like a rook.  You cannot allow his pieces here to become worth more than yours.  So yes although your bishop is in on the attack on h7 you need to trade it off as a defensive move here or the knights become monsters.

These are the two largest errors which I believe led to your loss.

Some people already commented on many of the moves, but check the movelist.

I do this far too often. When I'm a bit ahead I start playing sloppy and start making mistakes.

And there's a lot of stuff here that I can use to really improve my game. Thanks everyone for taking the time for me.

19. g4 was your problem

Ooh! Ooh! Try the online analysis.

By Kevindubrows request here's what the online analysis said:

6. Bg2?!, better was c4 (I'v got to learn to be more agrerssive with white I guess).

7. e3?! still c4

9. b3? Better was Qf3 (attacking the undefended f5 pawn).

10. ... Nbd7? better was Nc6

11. 0-0?! better was Nxd5 (winning a pawn).

12. a3?! Nxd5 still better...

15. ... Ng4? Better was Qe7.

16. h3?! Should've played Ne6 immediately.

19. g4?! The computer likes c4 leading to a decisive advantage for white.

20. ... Ne5? Better was Qd6 aiming a battery attack for h2.

23. f4? Qe2 leads to a decisive advantage for white. f4 keeps the position equal.

25. Qh1? As noted above a mistake. The computer likes Rfe1 over Rae1

25. ... Nf5? After Qe6 black can actually gain the advantage.

26. ... Ng3? Bb6 keeps the position equal.

28. Rf3?? It indeed lost the game outright for me. After Bb3 white retains the advantage.

31. Be1? Better was Bc1

32. Rd7?! Better was Rd3, which is still not winning but definetely better.

33. Rxb7? Bf2 was better.

34. Kf1?? The final blunder. Better was Bf2.

35. Kxe1?! Rxd6 loses less material.

So, most is on par with what everyone said before. Lessons to be learned (for me):

1. Be aggressive in the opening with white. I was scared to play c4 early and it cost me the initiative.

2. Don't play too fast. I missed some really good options to capitalize on my opponent's mistakes and did not no so. Not taking the pawn on move 11 was unnecessary and missing the Ne6 move the first time unforgivable.

3. Don't get lazy if you're ahead. I thought some easy trades would get me the game and I payed dearly.

4. Don't get distracted by possible checks if your opponent can gain material. I was so focused on the threat of 25. ... Qh4 that I completely ignored my other defences and played Qh1.

5. Don't protect your pieces at all cost. I was so scared of Nxf1 that I didn't consider the possibility that I could have a winning position after it. Rf3 protects the rook but loses the bishop and the game.

It's the standard chess.com analysis. strength 2000 for non-members.

I think 5 0-0 6 d3 7 Nd2 and 8 e4 (with or without Re1) would have been better