At the moment, it's Black to move. The correct idea is to play...2....Rc6The easiest draw idea. Since the White King wants to move ahead, cutting it on the 6th rank is a great idea! But what if the pawn moves?2...Rb8Waiting on the 8th rank doesn't work.3.Kg6Rb6+4.f6Now the Black Rook needs to cover a check on the 8th rank, but that's not the only problem.Rb85.Rg7+An important check, putting the Black King in an uncomfortable position.Kf8(5...Kh8is met with...6.Rh7+Kg87.f7+Kf88.Rh8+)6.Rh7Now there's a mating threat with Rh8.Kg87.f7+Kf88.Rh8+Ke79.Rxb8Winning the rook and the game. Now let's go back to see how Black defends.3.f6...3.Rb7If White waits, Black does the sameon the 6th rank.Ra63.Ra8+Kg74.f6+Rxf65.Ra7+Rf7draws immediately.3....Rc1The White King is not yet on g6, and before that happens Black takes a comfortable position from behind, to deliver many checks after Kg6.3...Rc84.Kg6Transposes to the lost positon we saw earlier.4.Kg6...4.Ra8+Kf7is equal.4.f7+Kf85.Kf6White is not on time for this. The Rook can go and cut the King on the 6th rank with Rc6+ or give lot of checks from behind.Rf1+6.Kg6Rg1+7.Kf6Rf1+8.Ke6Re1+4....Rg1+5.Kf5Rf1+6.Ke5Re1+7.Kf4Rf1+8.Ke5...8.Kg3Rxf68....Re1+Being unable to get cover from the checks, White has to accept the draw. If the King goes closer to the Rook, and leaves the pawn undefended, Black can attack it as well.9.Kd4Rd1+10.Ke3Rf111.Ra6Kf7The f6-pawn will fall and the game ends in a draw.