Early on I lost all my stats when I switched to the NYT. I was able to retrieve them all as my family had been competing and reporting their scores in our WhatsApp group every day. Since then I've kept a little piece of paper with 1 to 6 down the left-hand side, and every day I put a dot next to that day's score. It makes a nice visual bell-curve, sort of, though I'm not very tidy about it!