Marquee_K wrote:
I have noticed that whenever I have reached a milestone, let's say 2100 rating, and I am ready to quit after one more puzzle I find myself an hour later still doing puzzles and at 1900 rating. Is there an algorithm in place to make people spend more time on the puzzles and therefore the site in general? It's happened too many times for it to be a coincident
No, but for some personality types, "just one more puzzle" becomes a lot more. It's just normal psychology of reward at play, nothing specific to any algorithm.
I get that occasionally, where I'm close to a new high, then tilt trying to reach it, then try to get back to where I was before. It has nothing to do with the puzzle selection algorithm and all to do with my ego 
I have noticed that whenever I have reached a milestone, let's say 2100 rating, and I am ready to quit after one more puzzle I find myself an hour later still doing puzzles and at 1900 rating. Is there an algorithm in place to make people spend more time on the puzzles and therefore the site in general? It's happened too many times for it to be a coincident