Help with some sprint conversions

[Alcyallen]

What would a 9.4 100 yard dash be for 100 meters? I was thinking....10.30 meaning a 9.1 would be a 10.00. And all the 9.1 world recorder holders ran around 10.05ish.

Back in 64 when Hayes ran his 10.06 out of that shoddy Tokyo lane one (why was he there?) what would that be today on one of these tracks? No no he is the same guy just a different track. I got 9,95......no?

Just a question....if Jimmy Hines could have hung around until 72 does he beat Borzov in the 100m? Same thing with Tommie Smith, does he beat Borzov in the 200m?

[El Toro]

MileSplit has a calculator where you can convert different distances: https://www.milesplit.com/calc?time=9.30&event=100y

However, this calculator does not seem to reflect reality.

Helpfully, www.alltime-athletics has a list of electronic 100 yard times and a flag if they were recorded enroute to a longer distance. There are 47 of these but I only managed to match 15 with a 100m time, probably because the 100m list is not deep enough.

Anyway, the average difference for elite sprinters is 0.77 with a range of 0.75 (Bolt x 2) to 0.80 (Kim Collins). The average doesn't change for the top 5, middle 5 or slowest 5 times (9.83-10.08) whereas the MileSplit calculator gives a much larger differential that increases for slower times (0.85 - 0.87).

I always prefer reality to a model, so I'd recommend adding 0.77 to an electronic 100 yard time. The standard conversion from a hand time to electronic is 0.24 as the most likely difference but you'll never know for sure on any individual 100m. Was that 9.1 really a 9.0 or 9.2 or actually 9.1?

So for your 9.1h, 9.1h +0.24= 9.34e, then 9.34e + 0.77 = 10.11 over 100m.

Here's a table of the performances with the 100 yard split and the final 100m time, the difference, what the MileSplit calculator estimates from 100 yards to 100 metres and the MileSplit conversion minus the actual 100 yard time.

Athlete	yards	metres	m-yds	MScalculator	MScalc-yds
Asafa Powell	9.07	9.83	0.76	9.92	0.85
Asafa Powell	9.09	9.88	0.79	9.94	0.85
Justin Gatlin	9.10	9.86	0.76	9.95	0.85
Usain Bolt	9.14	9.91	0.77	10.00	0.86
Steve Mullings	9.19	9.97	0.78	10.05	0.86
Usain Bolt	9.23	9.98	0.75	10.09	0.86
Asafa Powell	9.26	10.04	0.78	10.13	0.87
Mike Rodgers	9.28	10.04	0.76	10.15	0.87
Xie Zhenye	9.28	10.06	0.78	10.15	0.87
Kim Collins	9.29	10.09	0.80	10.16	0.87
Usain Bolt	9.29	10.04	0.75	10.16	0.87
Mike Rodgers	9.29	10.08	0.79	10.16	0.87
Daniel Bailey	9.30	10.08	0.78	10.17	0.87
Andre De Grasse	9.30	10.05	0.75	10.17	0.87
Akani Simbine	9.31	10.08	0.77	10.18	0.87

[Alcyallen]

MileSplit has a calculator where you can convert different distances: https://www.milesplit.com/calc?time=9.30&event=100y

However, this calculator does not seem to reflect reality.

Helpfully, www.alltime-athletics has a list of electronic 100 yard times and a flag if they were recorded enroute to a longer distance. There are 47 of these but I only managed to match 15 with a 100m time, probably because the 100m list is not deep enough.

Anyway, the average difference for elite sprinters is 0.77 with a range of 0.75 (Bolt x 2) to 0.80 (Kim Collins). The average doesn't change for the top 5, middle 5 or slowest 5 times (9.83-10.08) whereas the MileSplit calculator gives a much larger differential that increases for slower times (0.85 - 0.87).

I always prefer reality to a model, so I'd recommend adding 0.77 to an electronic 100 yard time. The standard conversion from a hand time to electronic is 0.24 as the most likely difference but you'll never know for sure on any individual 100m. Was that 9.1 really a 9.0 or 9.2 or actually 9.1?

So for your 9.1h, 9.1h +0.24= 9.34e, then 9.34e + 0.77 = 10.11 over 100m.

Here's a table of the performances with the 100 yard split and the final 100m time, the difference, what the MileSplit calculator estimates from 100 yards to 100 metres and the MileSplit conversion minus the actual 100 yard time.

Athlete	yards	metres	m-yds	MScalculator	MScalc-yds
Asafa Powell	9.07	9.83	0.76	9.92	0.85
Asafa Powell	9.09	9.88	0.79	9.94	0.85
Justin Gatlin	9.10	9.86	0.76	9.95	0.85
Usain Bolt	9.14	9.91	0.77	10.00	0.86
Steve Mullings	9.19	9.97	0.78	10.05	0.86
Usain Bolt	9.23	9.98	0.75	10.09	0.86
Asafa Powell	9.26	10.04	0.78	10.13	0.87
Mike Rodgers	9.28	10.04	0.76	10.15	0.87
Xie Zhenye	9.28	10.06	0.78	10.15	0.87
Kim Collins	9.29	10.09	0.80	10.16	0.87
Usain Bolt	9.29	10.04	0.75	10.16	0.87
Mike Rodgers	9.29	10.08	0.79	10.16	0.87
Daniel Bailey	9.30	10.08	0.78	10.17	0.87
Andre De Grasse	9.30	10.05	0.75	10.17	0.87
Akani Simbine	9.31	10.08	0.77	10.18	0.87

That was very cool, thank you😀

9.1 hand timed guys Hayes had a 10,06, Hines and Greene 10.02/10.03 (9.95 altitude) Williams 10.07, so around 10.10 seems about right,

[JC100]

What would a 9.4 100 yard dash be for 100 meters? I was thinking....10.30 meaning a 9.1 would be a 10.00. And all the 9.1 world recorder holders ran around 10.05ish.

I'll do it from a different angle (which comes up with the same answer!)

Most of the 100 yard times of the past were timed with stopwatches rather than electronically.

This means there are two components: first, the difference between a time for 100 yards and 100 metres; and second, the difference between a hand times and electronic times (e.g. Hayes' 10.06 and Hines' 9.95).

100 yards is 91.44 metres, so a 100 metres equivalent time is simply adding on how long it takes to run that additional 8.56 metres. This will, of course, vary from runner to runner depending on if they are a faster starter and bad finisher or vice-versa. Then there is the track surface, wind etc etc.

10 metre split data for the 100 metres is uncommon, but looking at 19 cases for elite sprinters who did not slow down at the end of the race, their speeds for the last 10 metres indicates that running the last 8.56 metres increases the time at 91.44 metres (100 yards) by 8.25 per cent.

Regarding the conversion between hand times and electronic times, the traditional addition is to add 0.24 seconds (for both 100 yards and 100 metres). This is well supported on average by actual data but it does vary a lot from race to race as El Toro notes.

So, to convert a hand time of 9.1 seconds to an electronic time for 100 metres, first add 0.24 seconds, then add another 8.25 per cent. This gives a time of 10.11 seconds.

Looking at some of the 9.1 runners in the 1960s:

9.1 Bob Hayes (1963 AAU semi-final on an early synthetic track). This was a rare case where there was an electronic timer, which had Hayes at 9.40 seconds. Adding 8.25 per cent gives 10.18 seconds. The race also had a helping wind of 0.9 m/s, which makes the 100m wind-adjusted equivalent time around 10.22 seconds. Hayes ran 9.32 seconds in the final, with a 3.5 m/s tailwind, which would convert to a 100m wind-adjusted equivalent time around 10.25 seconds.
9.1 Harry Jerome (1966 Canadian National Championships). No other info. Another helping wind of 0.9 m/s, so will be around 10.20 seconds electronic for the 100 metres.
9.1 Jim Hines (1967 Houston). Helping wind of 0.8 m/s.
9.1 Charlie Greene (1963 NCAA, heat 4). Helping wind of 1.5 m/s. Electronic time of 9.23 seconds. Note that Greene actually ran faster in the final (electronic time of 9.21 seconds, wind +1.5 m/s) but his hand time was 'only' 9.2 seconds! This demonstrates the fickleness of hand timing, and Greene was arguably unlucky to not get a 9.0 here. The wind-adjusted equivalent time for the final is around 10.05 seconds. This was, however, at high altitude at Provo, so there is a vexed question of how to adjust for this.
9.1 John Carlos (1969 West Coast Relays, Fresno). Helping wind of 0.1 m/s.

In reality, I expect that most of the 9.1 times in history were partly the result of generous hand timing.

Just to be really controversial, here are all of Jim Hines' electronic times over 100 metres, except at high altitude, with some rough conversions for wind-adjustment since a lot of these had strong winds.

10.17 (+2.0) = 10.27 Modesto 1967
10.03 (+0.8) = 10.07 Sacramento 1968 (AAU semi-final)
10.13 (+3.3) = 10.30 Sacramento 1968 (AAU final)
10.44 (-3.5) = 10.27 Los Angeles 1968 (semi-final of the semi-final Olympic Trials)
10.38 (-1.9) = 10.29 Los Angeles 1968 (final of the semi-final Olympic Trials) The wind is given only as a 'head wind' so I've used the average of the two semi-final winds.

There are not many but they are quite consistent and its pretty obvious which is the odd one out. The Sacramento semi-final was held in the middle of a three hour period starting with Hines' run in the heats (wind +2.8 m/s) and ending with the final (wind +3.3 m/s). In between was this semi-final where everyone apparently ran far faster than they ever did before or after, just as the wind apparently dropped markedly. Can you join the dots? The Night of Speed is one of those sacred cows in track history, but it looks like a wrong wind measurement to me. Applying similar analysis to that which gives a wind of +5 for Flo-Jo's 10.49, you get a wind of at least 3 m/s.

Hines also ran four big races over 100 metres in 1967-68 which were hand timed only, with times of 10.1, 10.2, 10.1 and 10.3 (the winds are not known for some). On the natural tracks of the late 1960s, Hines was a 10.25-10.30 electronic timed runner over the 100 metres, corresponding to hand times of 10.0 or 10.1. On the synthetic track at high altitude in the Olympic trials at Echo Summit, Hines ran 10.11 seconds (zero wind). Charlie Greene's numbers are very similar.

Hayes was in Lane 1 in the 1964 Olympic final because the lanes were randomly drawn until 1988. Owens was in lane one in 1936, Crawford was in lane one in 1976 and Wells in lane eight in 1980.

Placed in a time machine, Hines likely beats Borzov in 1972, but not by much. Neither of them gets close to Hayes, however.

This turned out to be a log post, sorry!

[Alcyallen]

I'll do it from a different angle (which comes up with the same answer!)

Most of the 100 yard times of the past were timed with stopwatches rather than electronically.

This means there are two components: first, the difference between a time for 100 yards and 100 metres; and second, the difference between a hand times and electronic times (e.g. Hayes' 10.06 and Hines' 9.95).

100 yards is 91.44 metres, so a 100 metres equivalent time is simply adding on how long it takes to run that additional 8.56 metres. This will, of course, vary from runner to runner depending on if they are a faster starter and bad finisher or vice-versa. Then there is the track surface, wind etc etc.

10 metre split data for the 100 metres is uncommon, but looking at 19 cases for elite sprinters who did not slow down at the end of the race, their speeds for the last 10 metres indicates that running the last 8.56 metres increases the time at 91.44 metres (100 yards) by 8.25 per cent.

Regarding the conversion between hand times and electronic times, the traditional addition is to add 0.24 seconds (for both 100 yards and 100 metres). This is well supported on average by actual data but it does vary a lot from race to race as El Toro notes.

So, to convert a hand time of 9.1 seconds to an electronic time for 100 metres, first add 0.24 seconds, then add another 8.25 per cent. This gives a time of 10.11 seconds.

Looking at some of the 9.1 runners in the 1960s:

9.1 Bob Hayes (1963 AAU semi-final on an early synthetic track). This was a rare case where there was an electronic timer, which had Hayes at 9.40 seconds. Adding 8.25 per cent gives 10.18 seconds. The race also had a helping wind of 0.9 m/s, which makes the 100m wind-adjusted equivalent time around 10.22 seconds. Hayes ran 9.32 seconds in the final, with a 3.5 m/s tailwind, which would convert to a 100m wind-adjusted equivalent time around 10.25 seconds.
9.1 Harry Jerome (1966 Canadian National Championships). No other info. Another helping wind of 0.9 m/s, so will be around 10.20 seconds electronic for the 100 metres.
9.1 Jim Hines (1967 Houston). Helping wind of 0.8 m/s.
9.1 Charlie Greene (1963 NCAA, heat 4). Helping wind of 1.5 m/s. Electronic time of 9.23 seconds. Note that Greene actually ran faster in the final (electronic time of 9.21 seconds, wind +1.5 m/s) but his hand time was 'only' 9.2 seconds! This demonstrates the fickleness of hand timing, and Greene was arguably unlucky to not get a 9.0 here. The wind-adjusted equivalent time for the final is around 10.05 seconds. This was, however, at high altitude at Provo, so there is a vexed question of how to adjust for this.
9.1 John Carlos (1969 West Coast Relays, Fresno). Helping wind of 0.1 m/s.

In reality, I expect that most of the 9.1 times in history were partly the result of generous hand timing.

Just to be really controversial, here are all of Jim Hines' electronic times over 100 metres, except at high altitude, with some rough conversions for wind-adjustment since a lot of these had strong winds.

10.17 (+2.0) = 10.27 Modesto 1967
10.03 (+0.8) = 10.07 Sacramento 1968 (AAU semi-final)
10.13 (+3.3) = 10.30 Sacramento 1968 (AAU final)
10.44 (-3.5) = 10.27 Los Angeles 1968 (semi-final of the semi-final Olympic Trials)
10.38 (-1.9) = 10.29 Los Angeles 1968 (final of the semi-final Olympic Trials) The wind is given only as a 'head wind' so I've used the average of the two semi-final winds.

There are not many but they are quite consistent and its pretty obvious which is the odd one out. The Sacramento semi-final was held in the middle of a three hour period starting with Hines' run in the heats (wind +2.8 m/s) and ending with the final (wind +3.3 m/s). In between was this semi-final where everyone apparently ran far faster than they ever did before or after, just as the wind apparently dropped markedly. Can you join the dots? The Night of Speed is one of those sacred cows in track history, but it looks like a wrong wind measurement to me. Applying similar analysis to that which gives a wind of +5 for Flo-Jo's 10.49, you get a wind of at least 3 m/s.

Hines also ran four big races over 100 metres in 1967-68 which were hand timed only, with times of 10.1, 10.2, 10.1 and 10.3 (the winds are not known for some). On the natural tracks of the late 1960s, Hines was a 10.25-10.30 electronic timed runner over the 100 metres, corresponding to hand times of 10.0 or 10.1. On the synthetic track at high altitude in the Olympic trials at Echo Summit, Hines ran 10.11 seconds (zero wind). Charlie Greene's numbers are very similar.

Hayes was in Lane 1 in the 1964 Olympic final because the lanes were randomly drawn until 1988. Owens was in lane one in 1936, Crawford was in lane one in 1976 and Wells in lane eight in 1980.

Placed in a time machine, Hines likely beats Borzov in 1972, but not by much. Neither of them gets close to Hayes, however.

This turned out to be a log post, sorry!

That was a great read, loved it!

Totally agree that Hines beats Borzov who ran a 10.14 that day, and neither can hang with Bullet Bob. Borzov also running 10.14 in 76.

With the hand timed 9.1 guys mostly running 10..02 to 10.07 Steve Williams....a 10.10ish would work.

A shame we never saw Hayes, Hines, Carlos, Smith, Greene much after their Olympics. All but Greene giving the NFL a try, only Hayes making it.

That night in Sacramento was crazy, how many PR's, wow!

[El Toro]

JC100, thanks for some great input.

I expanded yesterday's table by using IAAF profile results to find the missing 100m times for pela's 100 yards but I deleted the MileSplit calculator columns because it's clear that calculator doesn't work well for this conversion.

With respect to MileSplit's increasing time between the two distances as speed decreased, this is observable but is very stable for the fastest runners. In fact, the 9.83-10.18 range was 20 performances with a mean of difference of 0.77s, the same mean as those under 10.00.

It's only after that the differences start to blow out but this may be due to the slower runners giving up at the end. I've done a table of ranges of 100m times and you can see that it's the maximum differences that increase to blow out the mean and the range.

RangeLow	RangeHIgh	Mean	Min	Max	Range
9.83	9.99	0.77	0.75	0.79	0.04
10.00	10.09	0.77	0.75	0.80	0.05
10.10	10.19	0.79	0.77	0.82	0.05
10.20	10.29	0.80	0.77	0.85	0.08

Full updated table sorted in order of fastest 100m times:

Athlete	yards	metres	m-yds
Asafa Powell	9.07	9.83	0.76
Justin Gatlin	9.10	9.86	0.76
Asafa Powell	9.09	9.88	0.79
Usain Bolt	9.14	9.91	0.77
Steve Mullings	9.19	9.97	0.78
Usain Bolt	9.23	9.98	0.75
Asafa Powell	9.26	10.04	0.78
Mike Rodgers	9.28	10.04	0.76
Usain Bolt	9.29	10.04	0.75
Andre De Grasse	9.30	10.05	0.75
Xie Zhenye	9.28	10.06	0.78
Mike Rodgers	9.29	10.08	0.79
Daniel Bailey	9.30	10.08	0.78
Akani Simbine	9.31	10.08	0.77
Kim Collins	9.29	10.09	0.80
Kim Collins	9.34	10.12	0.78
Isiah Young	9.34	10.13	0.79
Filippo Tortu	9.38	10.15	0.77
Simon Magakwe	9.38	10.16	0.78
Christopher Belcher	9.38	10.17	0.79
Lerone Clarke	9.38	10.18	0.80
Lerone Clarke	9.37	10.19	0.82
Kim Collins	9.39	10.19	0.80
Lerone Clarke	9.39	10.19	0.80
Harry Aikines-Aryeetey	9.41	10.19	0.78
Simon Magakwe	9.41	10.19	0.78
Mark Lewis-Francis	9.40	10.20	0.80
Dexter Lee	9.41	10.20	0.79
Dexter Lee	9.42	10.20	0.78
Ivory Williams	9.40	10.21	0.81
Sean Safo-Antwi	9.40	10.21	0.81
Ramon Gittens	9.42	10.21	0.79
Bryce Robinson	9.43	10.21	0.78
Trell Kimmons	9.37	10.22	0.85
Trell Kimmons	9.41	10.22	0.81
Mario Forsythe	9.42	10.22	0.80
Su Bingtian	9.43	10.22	0.79
Darvis Patton	9.45	10.22	0.77
Tyrone Edgar	9.43	10.23	0.80
Thando Dlodlo	9.45	10.24	0.79
Mark Lewis-Francis	9.47	10.24	0.77
Hassan Taftian	9.45	10.25	0.80
Kemar Hyman	9.46	10.26	0.80
Lerone Clarke	9.46	10.26	0.80
Richard Kilty	9.47	10.27	0.80
Dwain Chambers	9.47	10.28	0.81
Craig Pickering	9.49	10.31	0.82

[Atticus]

The only logical way is to look at the end time and estimate time for the last 10m.

We know the fastest 10m 'split' was a .81 for Bolt and that .85 is common for the elite. We also know that the 90-100m split is slower than the fastest.

For a sub-10 time, we can assume somewhere around .84 for that last 10m.
100y = 91.44y, so that's 8.56m short. .856 x .84 is .72 sec.

A 9.72 100m = 9.00 100y
100m in 10.00 = 9.28.