I ran 17:19 at my Conference meet in good conditions. Next Saturday I'm racing again on the same course, same conditions. However, with 600 to go I tried to start my kick and but couldn't as I had to take a crap (and the last 600 is largely uphill), so I could only maintain the same pace. Probably only about 3-5 seconds but still. I also was not super mentally tough (could have pushed it more from 1.5-2.5, maybe 5-10 seconds). I'm going to absolutely kill myself next weekend and not make the mistake of eating so close to my race next time. I should also be closer to my peak.
Obviously the exact percent chance thing is a joke, but it would be pretty fun to see where my odds stand.