One Mistake Costs You

So I was playing this game against this guy, He was winning positionally until he practially shot himself in the foot at move 16Qe7

Looking back on it, Being a 4min game, I was being smashed until he blundered.

Goes to show you, that one blunder or one bad move can completely undo you

What are your mistakes? (Or big mistakes your opponents made) that cost the game?

Don't worry. This is a safe place. We won't laugh at you much

15. Nd5, white gets some grip on the position. I think it's something to play for, even a pawn down , white can develop quickly with his open lines.

but yes. 10. e5 was the blunder

edit: I missed Bd4 xD thanks

Im not sure what you meant by "He was winning positionally..." unless you meant he had the game won (which he did) 

You missed 15.Bd4

Wow, that was a terrible blunder!

Yeah, it's sad since I actually saw Bd4 but for some reason forgot to play it

Actually no, I chose not to play 15Bd4 since e5 counters it

15...e5 loses a pawn

I believe you need to rethink your approach against the line black is playing.

In fact, I believe your opponent could of got a good position if he would of played 7...Ne7.

His position would turn into the Hippo Defence.

Which the Hippo Defence is considered very passive. However, Your set up is not that aggressive which means he will be able to get into the Hippo Defence very nicely.

I wrote an article explaining how Hippo Defence Players play this line.

You can see the move f6 was a poor move for black. Yet if the move 7...Ne7 would of been played trouble would of been on the white horizon.

http://www.chess.com/blog/X_PLAYER_J_X/hippopotamus-defence

You are very lucky. Your bishop on g5 would of came under heavy attack with pawn moves such as h6 and even g5 in some cases.

I believe you should consider the line you play against the move 1...e6.

In the game you played 2.Nf3 what is the reasoning behind this move?

Instead of 2.Nf3 what about the pawn move 2.d4?