1. Luck of the draw?
2. You changed your streak when you realized you were in 'bad form'.
3. You moved into a range of puzzles that had themes you were not familiar with.
4. Someone is sitting at the other end of the line messing with you.
I'm inclined to think it was #4. But don't tell them I know.
On Tactics Trainer here on Chess.com, does anyone else experience ridiculous streaks? For example, today I went from 1812 to 1737 in a matter of 15 minutes by getting like 12 problems wrong in a row. 15 minutes later, I was right back to 1800 after getting about 10 right in a row. In the losing streak, I felt that my vision was bad and I was in bad form, but I then inexplicably turned it around and felt in good form again. I can't find an explanation for this occurence and peculiar fluctuation in my consistency and Tactics Rating. Is it possible that the problems just get very hard for a streak? any ideas would be appreciated.