How is this a DRAW?

https://www.chess.com/analysis/game/live/140417664732?tab=review&move=151

it says on the end that the position was fair but he had a rook and i was going to make a queen, surely im winning? (im black btw)

This is what it says -

Kf7is a great move
This is the only move that works! This evades the check from the rook.

It does not say it is a draw, nor the position was fair in the link you provided.

I am not very good, but yes I agree that you can win if you understand how to, and are capable of getting whjte in a Lucciana position and then capturing the rook and mating from there.

As stated I am not very good, so I took this into Shredder and it shows 77.Rg4 is a draw. Black must promote to a Queen or Rook. KR vs KR is a draw. 77. .... f1=Q 78.Rf4+ Qxf4 is a stalemate position/draw.

That's a beautiful and unexpected stalemate to save the game.

There's a stalemate trick.

After white moves Rg4, if black promotes the queen, then white has Rf4+!!

If black moves the king, white takes the queen and goes on to win.

If black captures the rook Qxf4, then white is stalemated - they have no legal move available but they are not in check.