I think there's some luck involved. The days I do bad it's usually because I guess the wrong word/synonym and then I need to go back to correct, not because I'm stumped. This is also my theory why someone who has a massive vocabulary (e.g. @Yehuda57) does poorly.
Interesting. Some of it is definitely familiarity with specific common crossword words/hints that don’t necessarily correlate with your regular vocabulary. However, I find that most of us land pretty consistently in the same third/quarter each day.
Although I’ve typically finished in the top 3 or 4, I have been beat pretty consistently by some combination of you, biobook, and a couple of the others. The last 3 days I finished ahead of all of you (possibly with the exception of skyguy918).
Hence,
Am I getting better or are you all getting worse?