The position you're having trouble with was the subject of much dispute for around 150 years: from 1770 to 1920. It isn't seen much at the highest levels anymore, but it can cause trouble until you learn how to handle it. In my opinion, the best course for Black is to sacrifice a pawn in exchange for quick development.

Heh, Be2 is as far as I knew this line, seems everyone else knows it to move 10.

Whob is prfectly correct...!!

I love defending this as black\

wow ok christian kudos on that one... it would have totally taken me off guard. your right that Bf1 is totally counter intuitive carlsen threw it out there once. I will have to mention this for kids. Its a great surprise weapon

This game seems to be a prepared line by a serious GM.. the position is crazy though. I left in The notes by GM Vallejo Pons

great games tony, Ive never seen those. I really like b5, and ever since I made it a part of my rep I wasnt afraid of ng5, i actually look forward to it now :)

What do you mean, its perfectly fine for Black!

By the way, it's black to move.  My bad.

I've never faced that b5 line before.

unless Bf1 is playeds, it seizes the initiative

well it seems that after ..b5 unless white plays Bf1 black gains the bishop pair in an open position after ....Nd4. Its a nice idea.... The one game I found and posted where white wins is a bit tricky and took a GM with solid technique to pull it off so not 100% convinced.