On Friday, SwimSwam editor-in-chief Braden Keith published an editorial arguing that there are some pro-athlete facets to the decision to hold finals at the 2020 Tokyo Olympics in the morning.
One of his points was that there wasn’t clear evidence that morning finals sessions will lead to slower times. So I set out to gather some data on this topic from the most-relevant sample we have on the flip: the Beijing 2008 Olympics.
The last time the Olympics were held in Asia, the organizers set up the schedule in the same order as they will in 2020. Prelims were during the night session and semis/finals were in the morning.
At the 2000, 2004, and 2012 Olympics the schedule was a more traditional prelims in the morning, finals at night set up. 2016 was a bit of an outlier with prelims in the early afternoon and finals starting at around 10PM and wrapping at midnight.
We can get some idea of the impact of the altered schedule by comparing the 2008 Olympics to the Olympics with a more standard schedule. I compared the time change from prelims to semis, semis to finals and prelims to finals (for events without semis) for the same swimmers, individual events only. For example, in the prelims vs semi comparison, a single data point was Gary Hall Jr. in 2004 50 free prelims 22.04, semis 22.18, a time add of .6%.
Prelims vs Semis Average Time Change
positive change is slower (“added” time), negative is faster (“dropped” time)
| Men | Women | |||
| Change | N | Change | N | |
| 2000,2004,2012 | -0.3% | 477 | -0.3% | 461 |
| 2008 | -0.1% | 160 | 0.2% | 158 |
| 2016 | -0.1% | 160 | -0.1% | 160 |
Prelim vs Final Average Time Change (for events without semifinals)
| Men | Women | |||
| Change | N | Change | N | |
| 2000,2004,2012 | -0.5% | 72 | -0.3% | 72 |
| 2008 | 0.2% | 24 | 0.2% | 24 |
| 2016 | -0.1% | 24 | -0.2% | 24 |
Semi vs Finals Average Time Change (both at night or both in the morning)
| Men | Women | |||
| Change | N | Change | N | |
| 2000,2004,2012 | -0.2% | 239 | -0.3% | 239 |
| 2008 | -0.3% | 80 | -0.4% | 80 |
| 2016 | -0.1% | 80 | -0.2% | 80 |
In the years with a standard morning prelims/evening finals schedule, swimmers were noticeably faster in semis than in prelims. In 2008, with the evening prelims/morning finals schedule, on average women were slower in semis than in prelims and slower in finals than prelims in distance events. The men were slower in the finals of distance events and faster than prelims in semis but by a smaller amount than in the standard schedule years (-.1% vs -.3%).
Swimmers were a bit better in 2008 than normal years comparing their finals times to their semis times, but not by the margin they were worse in the previous round.
Analysis
There does seem to be an effect where semis and finals times are slower relative to prelims times in 2008. But is the different schedule the cause?
This data is from 2008, so the obvious first question is “What about the super suits?” The comparison is of swimmers times to themselves in previous rounds. I assume for the most part swimmers were wearing the same suit from one round to the next, so it doesn’t seem like the suits should be a big factor. If someone can present a compelling argument in the comments why super suits would change the way swimmers attack a prelims/semi/finals format meet, I’m all ears.
Another complaint I anticipate: the use of averages instead of medians. Medians are often better because of the skew that can be caused by outliers or asymmetric distributions. That doesn’t seem to be a problem here. The distributions are pretty symmetric and relatively outlier free. The shifts above are present in the medians as well. Here are the distributions for the prelims vs semi data that show the shift in the overall distribution of time changes.
Is the schedule shift the cause of the worse performance relative to prelims in 2008? Maybe. The suits could be to blame. Some other environmental factor could be the cause. The schedule does seem like a likely culprit. Swimmers aren’t used to finals in the morning.
Alternatively, this isn’t evidence that 2008 finals were actually slower than they would have been in neutral conditions. Perhaps swimmers went abnormally hard in prelims in 2008. Records were falling so fast in the super-suits and times dropped so quickly overall, that maybe it became harder to control energy in early rounds.
Personally, I think the most likely explanation for the shift in the data is that the morning finals/semis is a disadvantage. It’s the simplest explanation.
why is the number of swims by the women slightly lower (477-461 in 00,04,12 and 160-158 in 08)? did some who qualified for semis not swim for some reason?
DQ’s account for the 158 to 160 discrepancy. The 477-461 mismatch is because, upon further investigation, my spreadsheet is missing the 2004 women’s 200 fly semis.
Sometimes I really liked plain old timed finals. Exert my energy all at one time, all out. I cannot remember when I saw elite swimmers in a timed finals format. Get your lane based entirely off a provable seed time. I’m wondering whether we could get slightly faster top times if early energy did not get burned off in prelims, even with a day of rest. (Or maybe prelims help the finals time?) I keep thinking there must be a way to grow the appeal of elite swimming to a larger television audience. The knock-out races are interesting, but those swims often seem to decline as they progress through rounds. Logically, the same decline impacts swimmers having to go through… Read more »
Michael Phelps said it best, Any Olympic Athlete should be able to get up at any hour of the day to compete for a medal.
Didn’t some guy win a bunch of gold medals and another relay swimmer have an amazing anchor leg in 4 x 100 fr?
Ian Crocker in the 100 fly prelims in Beijing 2008 wore a jammer suit to the knees and almost missed the semis
This doesn’t really prove anything. Maybe the swimmers just swam faster in prelims than other years but the finals times were just as fast as expected.
Of course it doesn’t prove anything, and I mentioned the possibility of fast prelims in the article. But if the answer is: prelims were fast that year. The question becomes: why were prelims so fast that year? I don’t have a good answer to that. If anyone does, I’d be interested to hear it.
The schedule affecting people theory passes this test. Why were semis and finals a bit slow in 2008 relative to prelims? Because people were affected by the schedule. That is both a reasonable and simple explanation.
Fast evening preliminary swim can also be mental factor. If a swimmer swam fast in the morning final, they could be riding that momentum for fast evening swim (while traditionally they are not pushing as hard in the morning for prelim swim). Or mentally swimmers feel like they don’t need to “save” energy for another swim session on the same day, when they are swimming prelim in the evening. They are free to swim faster to give themselves better chance for a second swim. Elite swimmers in the latter heats then gauged their efforts based on times in earlier rounds.
Just some random thoughts.
Who cares if finals were slow relative to prelims if they were still fast? Maybe prelims were fast and finals were also fast. How about comparing games to games? I know about super suits but fans don’t care they just want fast swims. They want to see swimmers chase the world record line. I remember many world records going down at those Olympics. I’m not saying your stats are wrong just possibly misleading.
That could be a factor. If the introduction of supersuits had made it difficult for the top tier swimmers to predict what times they needed to do in the prelims, to advance to the next round, they might have swum a bit faster than normal, to be on the safe side.
If there’s any truth to that, the pattern between the top-8 semi finalists, and those placed 9-16, would differ slightly. Of course, the same uncertainty might remain through the semi final round and affect times made there as well, so you would also have to compare the top-4 finalists to the 5th-8th placed swimmers and that’s where it gets a bit complicated.
In non semi final events, it would… Read more »
I would love to see trial follow a similar format in order for things to be closer to the real games.
I assume that both the men’s and women’s Marathon running events will be scheduled to start at around 8AM or so. I’m sure these athletes will be able to perform at a high level.
Yes, but pretty much every marathon they ever run is scheduled to start between 6-9am.
That’s not the case for swimmers, who from a young age swim prelims in the morning and finals in the evening.