The French governing body for swimming (Fédération Française de Natation) recently released a data analysis booklet of each event raced at the Paris Olympics. In this data-packed guide, information including swimmers’ 25m splits, time spent underwater, total stroke count, and more is laid out in a table with a breakdown of each finalist’s information. Over the next few days, I’ll be choosing some of my favorite races from the Olympics and analyzing the data behind the world’s fastest swimmers.
This data gold mine, all in French, has four distinct sections: Laps (splits), Parties Nagées (Parts of the race swum), Parties Non Nagées (Parts of the race not swum, including the start, underwaters, and finish), and Mouvements (total strokes and such).
LOOKING BACK
This was an unbelievable race, with China’s Pan Zhanle breaking his own world record by 0.40 seconds, swimming a 46.40 to win the final by over a second, one of the biggest margins of victory we’ve ever seen in this race. Kyle Chalmers became a three-time medalist in this event, finishing second in a 47.48. All the swimmers in this heat were originally seeded within the top 8, except for Josha Salchow, who was entered at 13th. Chalmers and fourth-place Nandor Nemeth were separated by 0.02 seconds, with Popovici going 0.01 seconds faster than Nemeth and slower than Chalmers to win bronze. All eight men were under 48 seconds, the first time that feat has occurred in an Olympic final. The swimmers finished as follows:
- Pan Zhanle, China – 46.40
- Kyle Chalmers, Australia – 47.48
- David Popovici, Romania – 47.49
- Nandor Nemeth, Hungary – 47.50
- Maxime Grousset, France – 47.71
- Josha Salchow, Germany – 47.80
- Jack Alexy, United States – 47.96
- Chris Guiliano, United States – 47.98
LAPS (SPLITS)
Opening 50:
- Pan – 22.28
- Grousset – 22.61
- Alexy – 22.63
- Guiliano – 22.82
- Nemeth – 22.90
- Salchow – 22.93
- Popovici – 22.94
- Chalmers – 23.03
Closing 50:
- Pan – 24.12
- Chalmers – 24.45
- Popovici – 24.55
- Nemeth – 24.60
- Salchow – 24.87
- Grousset – 25.10
- Guiliano – 25.16
- Alexy – 25.33
Pan was 0.33 seconds faster than the next fastest competitor in both the opening and closing 50 of this race. The other seven swimmers experienced a flip-flop of sorts, with Grousset, Alexy, and Guiliano (all well established 50 freestyle swimmers) flipping first but having the slowest last 50 times. On the other hand, Popovici and Chalmers used their skillset as 200 freestyle swimmers to make up from their first-50 deficits and place second and third, relying on their impressive back halves. Chalmers was the only swimmer to open up his 100 in over 22 seconds, but was also the closest swimmer to Pan during the final 50.
One theory about how Pan was able to break his world record in a “slow pool” ties largely into his first 50 swim. He was able to get out very quickly, and in hitting the turn before the rest of the field, he was able to avoid the tumultuous wake from everyone else’s flip. Swimming in clean water is always preferred, and with Pan taking out his first 50 as fast as he did (this time alone would’ve placed 33rd in the individual 50, even when measured to the feet), he found his way around the worst of the chop.
PARTIES NAGÉES (PARTS OF THE RACE SWUM)
This section provides the swimmers’ times from 15m to 45m, as well as their times from 65m-95m, accounting for everything except the start, turn, and the finish. The following ranking is their total time spent “swimming.”
- Pan – 29.32
- Nemeth – 30.04
- Chalmers – 30.14
- Salchow – 30.19
- Popovici – 30.22
- Alexy – 30.57
- Grousset – 30.63
- Guiliano – 30.73
This was another statistic that was relatively consistent with the final rankings, which makes sense, given that the fastest “swimmers” are going to finish near the top in a race like the 100 freestyle. Pan was undoubtedly the fastest in these segments, which was vital in helping him break the world record by as much as he did. Another interesting thing to note is the two Americans near the bottom of this list. Both Guiliano and Alexy were not near their best times, but it hasn’t been uncommon to see American names on the lower end of the “swimming” rankings– more on that in the next section.
PARTIES NON NAGÉES (PARTS OF THE RACE NOT SWUM)
This section highlights the start, turn, and finish of the race, including reaction times, time spent underwater, distance covered underwater, time to hit the 15m mark, closing 5m time, and distance from last stroke into the wall. The following ranking is the total time spent from the start to 15m, 45-65m, and 95m to the wall (measured in seconds).
- Pan/Grousset – 17.08
- Guiliano – 17.25
- Popovici – 17.27
- Chalmers – 17.34
- Alexy – 17.39
- Nemeth – 17.46
- Salchow – 17.61
Fastest swimmers to 15m (in seconds):
- Grousset – 5.33
- Guiliano – 5.40
- Pan – 5.45
- Alexy – 5.55
- Chalmers/Nemeth – 5.61
- .
- Salchow – 5.62
- Popovici – 5.66
As I mentioned in the last section, American swimmers tend to have better auxiliary portions of their swim comparative to the entire race. We saw it with Nic Fink having the fastest time in the segment for the men’s 100 breaststroke, Gretchen Walsh’s quick underwaters in the women’s 50 freestyle, and now Chris Guiliano and Jack Alexy having some of the fastest starts amongst the men’s 100 freestyle field. Of course, this doesn’t hold true for every race, but it’s likely due to the influence of NCAA and SCY (short course yards) swimming on the American delegation. Yards swimming requires more out of a swimmer’s starts and turns than long course does, so it’s fitting that the swimmers who were raised in SCY pools will likely have better times in the starts/turns/finish segments of their races.
This portion also showcases Grousset, Alexy, and Guiliano’s talents as 50 freestylers. The trio had the three most efficient starts off the blocks, this metric determined by the distance traveled before the first breakout stroke divided by the time spent underwater. That ranking is seen here:
- Grousset: 12.92 meters underwater / 3.62 seconds underwater = 3.57 m/s
- Alexy: 12.14m / 3.49s = 3.48 m/s
- Guiliano: 13.64m / 3.95s = 3.45 m/s
- Popovici: 11.82m / 3.46s = 3.42 m/s
- Pan: 13.18m / 3.90s = 3.38 m/s
- Salchow: 12.76m / 3.80s = 3.36 m/s
- Chalmers: 12.22m / 3.65s = 3.35 m/s
- Nemeth: 13.05m / 3.94s = 3.31 m/s
MOUVEMENTS (STROKE)
This final section modeled the total strokes that each swimmer took during the race, and the following ranking shows from most strokes to least.
- Nemeth: 70
- Popovici: 69
- Grousset: 68
- Chalmers/Alexy: 67
- .
- Salchow/Guiliano: 65
- .
- Pan: 64
This stroke rate analysis section tends to circle back to the tenet of “swim your own race, whatever works for you.” None of the swimmers on the podium of the men’s 100 freestyle took the same amount of strokes as another, with Pan taking 64, Chalmers taking 67, and Popovici taking 69. Pan’s distance-per-stroke was admirable, as he managed to take the fewest amount of strokes and have the fastest time in the Parties Nagées section; however Josha Salchow had the best DPS rate.
Distance per stroke ranking (total distance spent above the water / total strokes)
- Salchow: 1.229 meters per stroke
- Pan: 1.220 meters per stroke
- Alexy: 1.197 meters per stroke
- Guiliano: 1.192 meters per stroke
- Chalmers: 1.171 meters per stroke
- Popovici: 1.167 meters per stroke
- Grousset: 1.131 meters per stroke
- Nemeth: 1.121 meters per stroke
For the previous data breakdowns, see the following articles:
For the full breakdown: see the booklet here.
I have to assume this data comes from high-res underwater footage of the entire race.
Oh, how I wish that was released publicly!
Bruh how is Alexy who’s 6’8 taking the same number of strokes as Chalmers
Chalmers isn’t that much shorter, maybe 6’4.
Could it be that Pan got so far ahead that the wave created by the line of swimmers at his feet gave him some extra propulsion forward? Amazing swim, not downplaying it at all.
I don’t think it’s that deep (lol), but he definitely did escape the waves the others were struggling with.
In a post-Olympic Interview, he covers the effects of the waves. For his 100m free final, he was so far ahead of the pack (a strategy he went in of balls to the wall), he never felt the waves, though he mentioned he did hit the waves for other races (4x100m free relay) and had to regroup for a 46.92 leg.
(So much for “expert” Brett Hawke’s (in)competence of different variables and how to adapt and overcome the barriers.)
Nathan Adrian theorizes (but defers to the scientists that study fluid mechanics) that the wall of waves behind the front swimmer could have that push.
He actually swam faster in the 4x100m medley relay, even adding the difference… Read more »
i don’t understand this. if you’re ahead of or even in line with the other swimmers, you’re in clean water. there’s not a wave at the swimmers heads… the wake forms behind the swimmers
Drag your finger along the surface of a bathtub. It leaves a wake behind, but also a little mound of water in front of your finger.
Whether that is effective on an Olympic-sized swimming pool, IDK.
the small region of compressed water in front of a swimmers head still takes time to travel sideways across into another lane. it’s this phenomenon of friction gradually travelling sideways that causes the wake to form.
it’s not like this mound of water is uniformly lined up across the pool. it only forms in front of the swimmer and takes time to traverse horizontally
Great article! Love all the data.
I was thinking that underwater speed can be a biased metric: since you slow down during your time underwater, this metric underrates swimmers with longer underwaters.
We could also ask: how much time did you save on your underwater relative to your average over-the-water speed. This stat will have a slight bias towards longer underwaters, but I think much smaller.
From the “PARTIES NAGÉES” section of the article, we can see that 100 freestylers go almost exactly 2m/s over the water (we could use their precise times, but this would penalize faster swimmers).
The formula for time-saved is: (Distance underwater) / (Over-water speed) – (Time underwater)
As an example, Grousset swam 3.57 m/s… Read more »
What stands out is that Pan is able to maintain his stroke rate and (unbelievably brilliant) DPS for the whole race. Popovici is also pretty good in this regard.
I remember an old Popov training video, where they note that most animals, when they want to go faster, increase their stride length, not frequency. On the other hand, swimmers tend to increase stroke rate at the expense of DPS, especially when fatigued.
Popov’s coach Touretski would’ve loved Pan’s swimming.
Very good observation. And, I think, in most cases, the easiest way to increase stroke rate is by grabbing less water, especially when fatigued.
Would love to see a ‘kick rate’ stat and how that relates to the stroke rate.
But how tho?
Should be fairly easy. All swimmers in the 100m free final swam with a 6-beat kick, so kick-rate is the stroke-rate multiplied by 6.
Pan was so far ahead that his wake made Chalmers go even slower.
Even with the Chinese rumors, isn’t this sort of swim on part with what Matt Biondi did? WR was 49.36 by Rowdy in 1981. Then Biondi went 48.95 in 1985, 48.74 in 1986, and then 48.42 in 1988. Meanwhile no other swimmer was within a half a second, with Chris Jacobs the next closest, but not until 1988 with 49.08.
At the ’85 PanPac’s Biondi split 47.84(!!) on medley relay & 47.66(!!!) on the 4×100 free! In a brief & goggles! No tech suit, no cap, no wedge on the block & no underwaters!
There’s a legend – don’t know if it’s true – that he messed up his start on the medley relay and swam his leg with his goggles in his mouth!
Shhhh, someone told us that the 100 Free is such a special event that big drops are impossible. 🤫