Why 0.24 Seconds is Added to Hand Times

Ever since the 100m was added as an official event by the IAAF in 1912, the quest to run a sub 10 second 100 meter has been the benchmark for sprinting supremacy.

Roger Bannister ran the sub 4 minute mile in 1954, but the 10.0 (HT) was the WR in 1960 by Armin Hary, and later equalled by Harry Jerome 3 weeks later.

But that 10.0 was officially 10.25 “electronic”.   Bob Hayes 10.0 was officially 10.06 in 1964.

The 9.9 run by Jim Hines, Ronnie Ray Smith and Charlie Green at the “US Trials” in Sacramento 1968 were 10.03, 10.14 and 10.10 respectively.  Steve Williams ran 9.9 in 1974 and Harvey Glance in 1976.

The 1968 Olympics saw Jim Hines run an electronic 9.95 (and that was in Mexico City’s altitude!)  Thus more men have run sub-4 minute mile than sub-10 second 100 meters when you consider 1954 and 1968 as the milestones.

It wasn’t until 1977 when FAT (fully automatic timing) were required for World Record purposes, despite having electronic timing in 1932!  Why so long?

The Difference between 0.14 and 0.24

Timers use the smoke (not sound) from the gun to start the stopwatch.  The closer you are to the gun, the better your visual reaction time to the smoke.  Thus for any race where the starter is NOT at the finish line, like 100m and 200m starting lines, the conversion is 0.24 seconds.

For the 400 meters (and 4x100m and 4x400m relay) it is 0.14 seconds.

But wait!  The 200m straightway is really far from the finish line!  I remember in high school (a long long time ago) I had a hard time seeing the starter for this race.  Imagine the timers!

In a research study back in 1973 using timers at the University of Giessen, they concluded:

1. timer and starter closest to gun (i.e. 400 meters) averaged a differential of 0.18 seconds
2. timer and starter at end of the 100 meter straightaway averaged differential of 0.24 seconds
3. timer and starter across the field of the 200 meter curve averaged differential of 0.26 seconds

The 0.24 conversion is “accurate”.

How they came up with 0.14 is another story.  Maybe it’s just a nice round number, just like the 0.100 reaction time for false starts.

Thankfully, we have electronic timing like Freelap that is affordable to put an end to this nonsense, whether you are timing yourself in practice or at time trials.