Grinding it out

Worked through 46 level 30's last night. Even though I did 58 the prior two nights, 46 took it out of me last night. I have noticed that as I get further in the problem set and get tired, the problems get harder. Problems have been taking me 2.5 houtrs or more this week. I wonder if one builds up mental stamina.

I should like to spend a few days studying the problems from level 20 and 30 that I got incorrect. My plan is always to go back and work through them in my spare time. I'm thinking there will be no spare time between now and the end of Circle Seven though. Even if I could find the time, I only have so much energy for chess in a day. Perhaps I could pause for a day or two to work on review. Seems like a good idea, but I'm a bit afeared to start messing with the plan.

I am really getting problem 461 down though. For some reason, it never registers as complete, so I have done it approx. 8 times now. Rook check, sac on h8, knight check and discovered attack on queen.

103 days down, 52 to go
612 problems down, 597 to go in Circle Two
Level 10: 97%
Level 20: 88%
Level 30: 76% (I was briefly in 77%)