http://www.sportsscientists.com lists the splits for each ten-meter interval of Bolt’s world-record 100m race like this: 1.85, 1.02, 0.91, 0.87, 0.85, 0.82, 0.82, 0.82, 0.83, 0.90.

If he had maintained top speed instead of celebrating over the last 20m, his time would have been 9.60, but apparently all elite sprinters slow somewhat near the end of the race, so that time is a bit optimistic. I’ll stick by my over-under of 9.63 for his future record.