♡ 50 ( +1 | -1 ) K & Rerrr.....I think so. To be honest I have always found that to be the easiest checkmate, there is little chance of a stalemate when in time pressure.
You just drive the King onto the last rank, leave your rook on the last but one rank, move your King (on 6th rank) towards the enemy king and wait for the Kings to face each other, then hey presto ! move your Rook onto the last rank and it is mate.
♡ 67 ( +1 | -1 ) VictorI highly recomend you learn to mate a lone King as quickly as possible with ALL piece combinations. Also I would suggest learning simple strategies regarding pawn endings and the concept of opposition. Most endgame books will have these items in the first chapter. You will be amazed how quickly you will be able to begin formulating plans in the middle game designed to place you in a winning endgame. Also combinations will start to come easier to you because you will see mating patterns you learned in those simple endgames take shape within a middlegame pawn structure.