Well, it's close enough to marathon day I had better have an idea of how I want to run this. So I decided on 5:35 pace, provided it feels okay during the race. How did I choose that?
My best workouts like the 21k, 1k medium, 1k hard, workout the hard parts I averaged under 5:30. Plus I've run a number of those kind of miles in workouts and races in the last four months. Considering how many 5:30 and below miles I have run, I consider that my best case scenario pace. In other words, if everything goes really well, I might run a 2:24.
A bulk of my workouts have happened around 5:45 pace, and that's the pace of my last marathon in 2011. Considering I have had a few workouts better than that go around, I am quite confident that I will PR at Chicago, however, there are always variable that make running harder. Still, even if things go poorly I see myself running 2:30
Finally, on my best long run in this cycle, I finished off with alternating 5:35 and 5:50 miles. They didn't feel easy, but they didn't feel terribly hard either. Considering it is in the range of likely paces for me to run, it is as good as anything. However, it's not slow and if I'm not feeling it in the first few miles, I have to back off. Regardless of the pace I end up averaging, I will cross that finish line exhausted.
So I'm aiming to run 5:35 per mile for a marathon, for a total time of 2:26. If things go better than expected I would like to run even faster. However, if things go poorly I still have a cushion where I can run 2:2X.
The truth is, we don't know how I will run Sunday. If I knew what I would run, I wouldn't run it, and chances are I would be disappointed I wasn't 15 seconds faster or something.