My coach told be if I'm able to consistently get a mix of run/walk that results in 15:00 a mile, it would be great and give us something to work with. 15:00/mile turns into a 6:33 marathon. I would sell my soul right now, cheap, for a 6:33 marathon in November.
I walk at between 17:00 per mile and 18:00 when I focus on walking quickly. I've done this pace for 9 miles. When I can run, I don't run fast. Pushing it, I run about 10:00 per mile but a jog pace is somewhere about 12:00.
So I did a math exercise. I figured if I jogged 2 minutes at a 12:00/mile pace, I would cover 1/6 of a mile. If I walked 3 minutes at a 18:00/mile pace, I would cover 1/6 of a mile. If I alternated this, I would have a mile done in 15:00. The more I mix in running, the faster I'll finish.
I expect math functionality to leave my brain somewhere early on race day so I figured I'd do the math now, write it down and put it in my special needs or transition bags, and probably doubt it during race day (see the stupid prediction). I'm going to test the math in my half Mary this weekend. I won't be anywhere near my PR but if I'm in the 3 hour neighborhood, don't feel that I want to chop off my foot because of the posterior tibial tendinitis pain, and have a successful century ride on Sunday, all will be good in the hood.
Now if someone asks me something along the lines of "if a train leaves Chicago........", the answer will be <6:33. The answer to every question might be <6:33 except the big question where the answer is <16:59:59.