My move was b7 and look what mentor has to say in the comments to the right.
I dare I can EASILY win this position with my move. My move should at least have been awarded as "alternate correct move" instead of bashing it right away.
Wait. I played black (and white) wrongly (1...Rxb7 is a right away disaster for black and he should instead play 1...Rc8 instead) for the first 3 moves after 1.b7 :(
But the idea is the same nevertheless. White still has winning advantage.