What people are failing to consider is pacing. Remember, in this situation Bekele has NO IDEA what time he's capable of. He'd do either one of two things:
- Set off too fast and completely burn himself out so he runs a time much slower than what he's capable of.
- Set off way too slow and then at the end think "Huh. That wasn't as hard as I expected."
You are all assuming that he magically sets out with a perfectly even pace, but pacing takes at least a few days, possibly weeks of training to grow accustomed to.
Even if he were physically capable of running sub-16, no way is he actually doing it.