Middle game blunders

This is a recent game I played with 15 (10) time control and won. I have been practicing chess puzzles & tactical problems and have drastically improved from where I was six months back. That was the time when I really started learning chess and it has become such a passion now!

But am not happy with the way the middle game was handled here - time and again I have seen similar patterns returning to my games. Step 21 could have been far better if I had played 21.Rb1 instead of 21.Nxf8. That and I noticed some other improvements too post match.

Can anyone help me figure out what I have to do to overcome such mistakes?

20.Rb1 actually better as an in between move, then  you win a piece or atleast traded up no matter what he does. The rest was well played at a quick glance.

Thanks Dinamo! I ran the PGN file through Fritz and it showed me couple of more improvements. I need to improve on my focus and attention for every move I guess - hope that will reduce my errors.

iam still not good at the chess position codes..but it was a good game..i dont understand how u can say u play better with bishops than knights..

Oh well .. I am probably not so good with bishops either :-) but knights are very tricky with their forks for me. comparatively bishops are more straight forward to deal with.