Rob -- I tweaked my right upper quad the day before China Grove.  It was fine until the finishing kick, made itself known, but didn't feel like I did any damage.  It's been faintly tight since.  Then it went completely OFF during some innocuous striders last TUE.  Felt like a pulled muscle, not that I have much experience with that.  Anyway, I've been resting it since -- I do not want any physical issues dogging me during late summer and fall marathon training.

Richard -- I use THIS AGE-GRADING CALCULATOR, which uses the most recent WAVA tables/factors.  THIS ONE is nice, too.