Help me analysing this

Oct 8, 2010, 1:43 PM |

I had this game recently and i decided to analyse it with computer analisys... but i am sure that what the analisys mark as a blunder, it's no at all a blunder

so here is the game


So my questions are... about
17... f4 (and 18... Rf5, because that's why f4 was for)
20... Bb7... because it is was not a blunder.. maybe was not the best, but not a blunder