How Accurate Were the Women’s Pan Pac Medal Predictions?

Photo Courtesy: Swimming Canada/Irwin Wong

By Brian Palaschuk, Swimming World College Intern.

Back in May, we used World Junior Swimming Results to predict the medal table of the women’s Pan Pac meet, which can be viewed here. Now that the 2018 Pan Pacific Championships are over, how accurate were those predictions?

A Reminder of the Methodology

In order to predict the medal table, first, the ratio of the average medal totals from World Juniors in 2011 and 2013 to Pan Pac medals in 2014 was calculated. Next this ratio, alongside the average World Junior Championship medal totals from 2015 and 2017, was used in order to predict the medal table of the 2018 Women’s Pan Pac meet.

Using those rations, the medal table came out as follows:

Country2015-2017 Average Junior Medal Total (Stroke 50’s Removed)2014 Conversion RatioPan Pacs 2018 Predicted Medal Totals
United States81.7514

However, this medal table was adjusted according to some trends that were demonstrated elsewhere in the data set. In 2014, the home team of Australia converted at a much better rate than they had in previous years. Using this knowledge, the medal table was adjusted slightly in Japan’s favor. Additionally, New Zealand collected three medals in 2014 from Lauren Boyle, which was unlikely to occur in 2018.

Adjusting for these two factors, the medal table came out as follows:

CountryAdjusted Prediction: 2018 Pan Pac Medal Totals
United States17

Here is a comparison of the quantitative prediction, the adjusted prediction, and the actual 2018 results:

CountryQuantitative Medal PredictionAdjusted Medal PredictionActual Medal Totals
United States141722


2018 Pan Pacs - 4x200m Freestyle Relay Gold

Photo Courtesy: Swimming Australia/Delly Carr

Using Australia’s 2014 conversion ratio of 2.67, the model predicted them to finish the meet with 12 medals. However, despite Australia retaining a strong core of swimmers, it was predicted that they would convert slightly worse after losing the home field advantage.

Australia defied that expectation, once again converting their Junior medals into senior medals at a rate of 2.67 Pan Pac medals per World Junior medal and once again coming home with 12 medals.



Photo Courtesy: Swimming Canada/Irwin Wong

Canada tends to convert their Junior medals at a worse rate than their competitors. In 2014, they produced 1.1 Pan Pacific medal for every World Junior medal – half that of meet leading Australia’s 2.67. The model predicted Canada to perform similarly here and produce 10 medals.

Canada fell short of this expectation, producing only 7 medals, or a Pan Pac medal conversion ratio of 0.78 medals per World Junior medal. Although this conversion is much worse than in 2014, it falls in line with their usual junior to senior conversion performance relative to other nations.



Photo Courtesy: Rob Schumacher-USA TODAY Sports

In 2014, Japan converted their World Junior medals at a ratio of 1.1 Pan Pac medal per World Junior one. In 2015 to 2017, Japan almost doubled their World Junior medal total from 2011 to 2013, going from 4.5 to 8 medals. Using their 1.1 conversion ratio from 2014, the model yielded nine Pan Pac medals to the Japanese in 2018. However, it was adjusted to 10 medals in attempt to account for the home field advantage.

At the 2018 Pan Pacs, Japan produced exactly 10 medals. This gave them a conversion ratio of 1.25 Pan Pac medals per World Junior medal, which is in line with the home field advantage expectation. This improved conversion ratio is still far behind the U.S. and Australia but much better than Canada’s 0.78 ratio.

United States


Photo Courtesy: Peter H. Bick

Using the United States’ 2014 conversion ratio of 1.75 Pan Pac medals per World Junior medal, they were predicted to produce only 14 Pan Pac medals in 2018. This total is low for a team as strong as the United States, which was accounted for in the adjusted prediction, shifting non-charter medals to the United States’ total, giving them 17 predicted medals.

In 2018, the United States greatly outperformed this estimate, winning 22 medals. This yielded an incredible conversion ratio of 2.75 Pan Pac medals won per World Junior medal. This conversion ratio is due in part to an unusually low average medal total of only eight at the World Juniors in 2015-2017 compared to the 12 that they averaged from 2011-2013.

Also note that this model allowed China to win three medals, but they were largely a non-factor at the meet as they saved their top swimmers for the Asian Games. This, coupled with Canada’s under performance, helped the United States to their excellent medal total and 2.75 conversion ratio.


The meet turned out much like how the model predicted, and several trends previously established continued to ring true.

Canada and Japan perform very well at the junior level compared to the senior level.

In 2018, much like in 2014, Canada and Japan converted their Junior medals into few senior medals. While Japan was better in 2018 than 2014, their conversion ratio of 1.25 pales in comparison to the 2.6 and 2.7 of Australia and the United States respectively. Similarly, Canada’s average of nine World Junior medals yielded them only seven medals at the relatively less competitive Pan Pacs.

Australia and the United States are relatively better at the senior level.

This is especially true of the United States, who averaged only eight World Junior medals in 2015 to 2017 to Canada’s nine and Japan’s eight. This is in spite of the fact that they more than doubled both of their medal totals at the 2018 senior Pan Pacs. Australia converts poorly as well – their junior team managed to average only a paltry 4.5 medals, while their senior Pan Pac team was able to amass 12.

This methodology is certainty a useful measure for the overall development of swimmers across the Pan Pac nations, and swimming fans can use this technique to predict future senior championship meets, including the 2019 World Championships.

Swim Nerd Tid-Bit

World Junior Medalists played a large role in the medal race at the 2018 Pan Pacs. The 2015 to 2017 World Junior medalists contributed to 10 of the medals won at the 2018 Pan Pacs, and seven unique medalists went on to win a medal at the 2018 Pan Pacs.

All commentaries are the opinion of the author and do not necessarily reflect the views of Swimming World Magazine nor its staff.