Well that makes absolutely no sense. If you hand time a 30 or hand time a 60 it’s going to be “off” by the same amount.
Not sure about the difference between 30 and 60 m, but as the distance gets longer, you should be more and more accurate vs. FAT. I would pay more attention to the start (for whatever “method” you are using), as the speed is high at the finish line anyway -depending on the level of the athlete, of course. In any case, I would be consistent whatever the distance…
Perhaps it is complete nonsense. However, I was just thinking that maybe the closer the timer gets the easier it is for him to sense your first movement, therefore maybe it wouldn’t be accurate if you use .65 or .5 or .6 or whatever, so maybe to make up for this stagger the times by .1 or something upwards per 10m. Haven’t tried it just something i thought about.
also keep in mind how the naked eye perceives a runner crossing the finish line. Some people go by the leg, torso, and sometimes after the person has crossed. Although not deliberate, it does happen. One ounce of mental distraction and even I look like all-world! 
ben woudl have walk them both… 633@60ةثفقث
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In case anyone is curious, analysis of Ben’s splits from Seoul show that he HAD to have taken 4.37 for the first 40 yards. This assumes that the splits are accurate to the 100th. That time includes his reaction time of .13 seconds.
The same analysis of Mo’s 9.82 run show that Mo took 4.34 for the first 40 yards, also including a .13 reaction time. The splits from that run are a little unusual at the start and I don’t know their accuracy.
The numbers I have for Mo are:
0.132
10m:1.83
20m:2.83
30m:3.75
40m:4.64
50m:5.50
60m:6.33
70m:7.16
80m:8.02
90m:8.91
100m:9.82
This puts their running times at 4.24 and 4.21 respectively.
First of all, how many of you have ever been to an official NFL combine?
Second of all, How many of you have actually timed NFL and Arena players?
Yes it does.
Here’s why:
The first table shows Maurice Greene’s split times and average speed over the first five 10m sections.
Column 1: Segment
Column 2: Interval Time
Column 3: Average speed over Interval
0-0m 0.13 0m/s
0-10m 1.70 5.88m/s
10-20m 1.00 10.00m/s
20-30m 0.92 10.87m/s
30-40m 0.89 11.24m/s
40-50m 0.86 11.63m/s
40 yards is exactly 36.576m. Consider the first 6.576m, and the second 3.424m of the 30-40m section. His times for them must add up to 0.89 seconds. The table below shows possible times and the speeds that he’d need to run to achieve those times.
Column 1: Possible Time for 6.576m
Column 2: Average Speed over 6.576m
Column 3: Possible Time for 3.424m
Column 2: Average Speed over 3.424m
.56s 11.74m/s .33s 10.38m/s
.57s 11.54m/s .32s 10.70m/s
.58s 11.34m/s .31s 11.05m/s
.59s 11.14m/s .30s 11.41m/s
.60s 10.96m/s .29s 11.81m/s
.61s 10.78m/s .28s 12.22m/s
We know the second speed in the above table must be higher than the first speed.
We also know that both sections in the above table must be faster than 10.87m/s, and slower than 11.63m/s, since those are the average speeds of the two 10m sections surrounding the 30-40m sections.
This leaves us with only .59 for the 6.576m, so his first 30m took 3.75seconds, and the next 6.576m took .59 seconds, for a total of 4.34 seconds for the 40 yards. This is within 0.01 if the splits I have are accurate.
I said nothing in my previous post about NFL players or their times.
This has been covered in depth already. Do some searching.