Decathlon statistics

[olorin]

Since I have spare time until the Olympics and no competition to follow, I decided to use my decathlon database to answer several questions that I never had the time (or motivation) to answer before.
While I know that this is not most people cup of tea, I hope that at least some of you (PJM?) will find it interesting. I will try to keep the technical part as simple as possible, but the sad truth is that if you do not like numbers and statistics then you shouldn’t read past the bottom line (which conveniently will be usually at the beginning).

So, without further ado let’s start with the first question

[olorin]

Do all decathlon events have the same importance?

The question of whether points are awarded equally among the 10 events is typically asked in relation that to the total number of points in each event. Even a casual look in the results show that the three throws and the 1,500 give on average less points then the other six events in the decathlon. This observation led to the erroneous conclusion that decathletes that are better in the throwing events (or the 1500) are in disadvantage compared with other decathletes. The following (hypothetical) table illustrates why it is not the case.

	Bad	Average	Good
100	800	900	1000
JT	600	750	900

As you can see from the table even though in all levels the 100 gives more points than the JT, it is more important to be good in the JT than in the 100. For example, a decathlete that is good in the 100 & average on the JT will score 1,750 points comparted with 1,800 points for a decathlete that is good in the JT and average in the 100.
In short, it is not the absolute number of points that is important but rather the relative points in each event (aka the slope).

So, consistent with this idea I calculated the difference between good and bad decathletes across the ten events.

The bottom line – all events are not equal. The two technical events PV & JT offer the highest rewards for those that are good on them while the 400 & 100h the smallest.

[olorin]

Technical notes and full results:

Until today there were 1,060 performances above 8,200 points. This is the data I will use to all my analyses.
To answer this question, I divided these performances to 10 even groups (decile) in each event and compared the score of the best and worst group. For example, in the 100m the top 10% ran 10.55 or faster and scored on average 994 points. The slowest group ran above 11.19 and score on average 800 points. This suggests that a good 100m runner will outscore a bad one by 194 points.
The table below presents these differences across the 10 events

Events	Difference
PV	287
JT	284
1500*	264
DT	228
HJ	223
LJ	216
100	194
SP	190
110	173
400	166

* relatively large part of the difference is because some decathletes have really bad results. Probably because they lost interest and decided to jog.

[lonewolf]

Thank you, olorin, fascinating stuff.
Now, if I could just back up seventy years, learn to PV, grow half a foot, gain 50 pounds (without losing sprint, jump, and 1500 ability) I could have been a "contendah."
Assuming, I was not DQed for illicit gym sweeping and consumption of uncastrated hog meat.

[bambam1729]

Technical notes and full results:

Until today there were 1,060 performances above 8,200 points. This is the data I will use to all my analyses.
To answer this question, I divided these performances to 10 groups in each event and compared the score of the best and worst group. For example, in the 100m the top 10% ran 10.55 or faster and scored on average 994 points. The slowest group ran above 11.19 and score on average 800 points. This suggests that a good 100m runner will outscore a bad one by 194 points.
The table below presents these differences across the 10 events

Events	Difference
PV	287
JT	284
1500*	264
DT	228
HJ	223
LJ	216
100	194
110	173
400	166

* relatively large part of the difference is because some decathletes have really bad results. Probably because they lost interest and decided to jog.

What about the shot put?

[noone]

Very interesting. Intuitively, I would have pretty much guessed the order correctly. Before the 400, I tell myself “who cares, they’ll all run between 48 and 50 seconds”.
So the last four events are the most important ones! This explains the Niklaus Kaul effect!

[KevinR]

Pretty cool stuff, here. Feeds the monkey for those of us who delight in statistics.

[olorin]

What about the shot put?

Thanks Bambam,
Added (190)

[deca]

That is a very cool analysis. Never looked at it that way. Almost makes it worth playing around with an entirely different training paradigm! As a Master's athlete, I could totally get into training for events in that order of priority as a novel approach.

[olorin]

Very interesting. Intuitively, I would have pretty much guessed the order correctly. Before the 400, I tell myself “who cares, they’ll all run between 48 and 50 seconds”.
So the last four events are the most important ones! This explains the Niklaus Kaul effect!

If we calculate each performance in the decathlon relative to the average performance of all decathletes we have a good measure of the quality of the performance.
For example, Warner recent 10.14 is worth 1062 points.
The average of all decathletes (above 8200) in the 100 is 888 points.
Suggesting Warner mark is worth 174 points above the average decathlete.

Kaul (2019) gained 69, 35, 255, 130 compared to the average decathlete in the last four events.
His score in the JT (255*) is the second best mark behind Tim Bright 5.70 in Seoul (scored 8216).
* Kaul mark was 79.05 and he got 1028 points, the average score of all decathlete is 773 leading to 255 points gain.

[cigar95]

My sense is that with the technical events, it's "easier to be bad". To "werf the speer" or "spung the stab hoch", you have to do basic things right every single time. Whereas once you're at some level of fitness and with your own natural abilities - and all of the top guys are very fit - you're going to run more or less the time for 400 that everyone expects you to run.
I'm a little surprised that the 110h isn't higher because it's easy to make mistakes in the hurdles.

[olorin]

My sense is that with the technical events, it's "easier to be bad". To "werf the speer" or "spung the stab hoch", you have to do basic things right every single time. Whereas once you're at some level of fitness and with your own natural abilities - and all of the top guys are very fit - you're going to run more or less the time for 400 that everyone expects you to run.
I'm a little surprised that the 110h isn't higher because it's easy to make mistakes in the hurdles.

The results are not driven by the poor group being extra poor in the technical events but also by higher rewards for being good.
For example, when we will calculate the difference between the best group (highest decile) and the median (so there is no effect of weak performances) the PV and the JT are still with highest spread (146 & 137). Most of other events have a spread of ~100 points and the 400 & 110h only ~80 points .

[IloveFelix]

I found this very interesting, Olorin!

Thanks a lot!

[cigar95]

The results are not driven by the poor group being extra poor in the technical events but also by higher rewards for being good.
For example, when we will calculate the difference between the best group (highest decile) and the median (so there is no effect of weak performances) the PV and the JT are still with highest spread (146 & 137). Most of other events have a spread of ~100 points and the 400 & 110h only ~80 points .

I didn't fully think through my observation, nor phrase it very well. Let me try again, while acknowledging there will be some degree of over-generalization just to keep from typing several pages. Perhaps revising my remarks to the point of becoming Captain Obvious - though I hope not.

Performance in each of the 10 events depends critically on both the innate ability and the fitness of the competitor. But for the jav and the vault, the mastering of the technical skills and executing them properly each time are also paramount. There are not as many "fine-grain" technical skills needed to optimally run the 400 - with apologies to Michael Johnson, who ran it quite optimally. So the technical events add a third degree of variability in each performance, which is something that will contribute at both the high *and* the low end.

If the technical events *didn't* show more variability in their scores, we might suspect an issue with the tables themselves.

I'm wondering if this might be an issue with the tables for the high hurdles. Whacking a couple hurdles can really costly in terms of performance - you'd think that would be reflected in variability of the scores, and at least keep the hurdles away from the bottom rungs of the ladder. One possibility is that the hurdles are an event where decathletes are generally going to be pretty good, so these bad mistakes aren't as frequent. Another possibility is that when they make really *bad* mistakes, the score suffers badly enough that they don't score over 8200 and don't make it into the database. Certainly this would be the case for a fall and dnf.

[noone]

Kevin Mayer ranked the events according to "danger", the risk of getting 0 points. I believe the order was PV, 110, LJ, DT, JT, HJ, SP, the flat runs. I would guess there have been countless 0's in the 1500 but due to athletes being out of contention