I'm not as good at binary digits as I used to be. And I can't put my finger on why - whether I'm going through them too quickly now for them to stick in my brain like I should, or if I'm just getting old. But I'm thinking of trying out new approaches to see if anything helps.
Currently I go through 760 digits (one journey), then review them, then move on to the next journey, review that, and so on until I run out of time. In my very very limited experimentation in the past, I found that a third viewing didn't improve my recall very much, but maybe it actually would help now. I don't think I could look at enough digits in 30 minutes to make it worthwhile, though. Or I was thinking of slowing down and taking more time with the recall - if I can go through six journeys with a slow-and-accurate second look, and get them mostly right, that would be more than acceptable, but I think that would be a stretch. It needs working on, anyway. It's high time I started experimenting more, memory-wise.