Puzzle 1508

http://en.lichess.org/training/1508

This puzzle had a very high rating (over 2300), yet I found it to be significantly simpler than many rated in the ~2000 range. Normally I spend about ~5-7 minutes on a single puzzle <2200 but this one took under a minute. Was wondering if anyone else feels the same.

The rating depends on the percentage of people solving the problem, as far as I see. In this particular case, I think most people try 1. Re6 with clear with because 2. Qc6 and 3. Qa8 are coming. But this is a wrong solution because there is an unobvious 1. Qf4 2. c4 mate :)

2. Qe4+ Kd5 3. Qe5# is a common mating pattern. I would guess this is where a lot of fails come from.

Also, the rating does not depend on the percentage of people who solve a problem, but acts the same way as the rest of the ratings this site uses. A pass/fail is treated like a win/loss, and ratings of the player and problem are adjusted based on a formula.