The Editor, Sir:

This is in response to the Devon Dick column of July 16.

Mr Dick,

Your reasoning that Michael Johnson ran two 100m races back to back and both were 100m world records is seriously flawed. The current 100m world record time of 9.72 is from rest, not a running start.

A second 100m would begin at full speed, not from the rest, so an athlete like Bolt would have a faster time over the final 100m. Therefore, you cannot simply multiply by two. Additionally, Bolt's first 100m probably would also be slower than 9.72 because the 200m involves a turn.

In his prime, Michael Johnson may have been able to run a 9.72 over the final 100m of a 200m race, but it would not have been from out of the blocks. He was never able to run a 9.72 from out of the blocks. That was why his race with Donovan Bailey was modified to 150m.

I am, etc.,

CHRIS C.

cacarter10@verizon.net