Analyzing Trends and Outliers in Women's Olympic Swimming

Oliver Franz | 8/2/2024

Topics: Minitab Statistical Software, Outlier Test

As the first full week of the 2024 Summer Olympics ends, we thought it would be an ideal time to explore historic trends in women’s long-distance swimming events. We’ve already predicted this year’s medal count and spoke about how one of Minitab’s own is helping to put the games on, but this analysis sheds light on how the longer swimming races have evolved and highlights the key performances that have defined them over the years.  

Specifically, we analyzed trends in the 800 m women’s freestyle, and we also wanted to see if Katie Ledecky’s gold-medal performance this year in the 1500 m women’s freestyle was a statistically significant outlier.  

 

800 Meter Women’s Freestyle Trends 

First, we visualized past winning times in this event to see if we could identify trends. We converted winning times from minutes and seconds to seconds and used Minitab’s Graph Builder to generate a line plot of winning times over the years:  

We were able to demonstrate how times have (overall) been much faster, especially since 2008. And there a 23.1 second difference in the winning times when you compare the 1996 winner (Brooke Bennett) to the 2016 winner (Katie Ledecky). 

We also used time series to generate a projection for the final on Saturday. Time series analysis examines data points collected over time to identify patterns and predict future trends based on historical trends. Here are the results:

Based on trends, Minitab projects that the winning time will be roughly 8 minutes and 5.4 seconds in the 2024 Olympics. This, of course, does not account for a potential super-human performance by the sport’s current best long-distance swimmer.  

 

1500 m Final, an Outlier? 

Speaking of that swimmer, Katie Ledecky, we wanted to see if her Olympic-record setting result in the final on Wednesday, July 31st 2024 was indeed a statistical outlier.  

This can be done easily in Minitab. Under the “Basic Statistics” menu, you can simply select “Outlier Test,” which is exactly what we did. We plotted finishing times from the final. Here are the results: 

Although Katie Ledecky’s performance was impressive, it was not an outlier (statistically speaking), though you wouldn’t know if it you were watching in real-time! 

 

Will there be an outlier in the 800 m final? 

With Minitab, we were able to project a possible finishing time for the winner of the 800 m women’s freestyle final and analyze the results from the 1500 m final.  

What we can’t tell you yet is whether that winner will be a statistically significant outlier—you'll just need to follow us on Instagram and LinkedIn to stay up to date with all our Olympics analysis and insights to see if it is!  

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