si botak said:a quick google search suggested around 13% of energy in wind resistance.
so over 100m 10% more resistance would be 0.1-0.2s difference. stride length, cadence, wind resistance, etc would all have some role at start, but I have no idea about how much effect each has as I'm not a sports scientist.
Suppose a longer stride and lower cadence makes it harder to accelerate though (but that's just a guess).
I don't think Bolt is the fastest out the blocks, I would think air resistance might effect a smaller athlete more though