Over 1700 at Chess Tempo

I managed to creep over 1700 at ChessTempo.

In fact ,I achieved this earlier in the year, but then, even though I kept above 1700 for some time, I  hit a very variable streak, rocketing up, but just as quickly dropping back to almost 1600.

Its taken me a month to edge up to within 1700, but somehow just not quite making it.

However, re-focusing in the last week has allowed me to regain the last of those 100 points to go over that 1700 limit again.

In the process, I have managed a continuous 42 weeks of problem solving, and have just completed 89 consecutive days as part of that. Technically, the number of days is almost double, but a software glitch linked to a being in a different time-zone cost me a missed two days.

Below is the problem that took me above 1700 ( to 1700.9 to be precise ), and it is a satisfying one.

White to play

The pawn, Knight and Rook combine to suggest a confinement of the King, but is there enough to force a mate ? 

That is the question to be answered, and although it took me more than the average of 6:20, I found that the answer was "Yes", and proved it.

Solution

To show that pride does indeed come before a fall, the below diagram shows me as over-confident, assessing both the solutions I had found, but through a lack of proper calculation and blindness, over-looked an obvious Black response, chose the wrong move, and dropped nicely under 1700 again.

White to play

Solution if required.

Now, though, I'm back above the line and on a slow and steady upward course.