5K won't be accepted for POT - it has to be a 10K or longer, per rD:
- Proof of time must be provided from an officially timed race reflecting results after January 1, 2015 and must be one of the below listed distances. Runners will be placed in the last corral if the appropriate race distance is not submitted for Proof of Time.
- Half Marathon – 10K, 12K, 15K, 10 Mile, Half Marathon or Marathon
- Full Marathon – 10 Mile, Half Marathon or Marathon
We don't know exactly how corrals will be broken down, but a 13:00 10K pace would certainly not correlate to the last corral. The last corral is supposed to be for those who do not submit POT at all, then a few more corrals before it for slower times. Remember that the minimum required pace is a 16:00 mile, so 13:00 would be placed ahead of everything between 13:00 and 16:00.