And how far out from the race do you prefer to run it?
It would seem that the closer that you come to simulating the actual race, the better the prediction. In the spirit of the Daniels philosophy of 'lowest stress for maximum benefit', I'm curious: what is the least stressful workout that you would personally perform to give you an idea of what kind of 5k shape you're in. I'm sure it's different for everyone based on history, strength/weakness profile and mileage.