A ranking system which allows men and women to compete directly and obviates bodyweight classes

Or: Ending the hegemony of the heavy

The current ranking system

At weightlifting competitions, men and women compete separately. Each gender is further divided into bodyweight classes. Rankings are determined within the gender and bodyweight categories by total amount of weight lifted.

The categories exist because a female weighing 87 kg can lift more than a female weighing 55 kg. The heavier female has more muscle mass than the lighter female; the amount of weight a person can lift scales with muscle mass. Furthermore, a male weighing 87 kg can lift more than a female weighing 87 kg.

The categories must exist only if the ranking metric is total amount of weight lifted.

An inclusive ranking system

Work done at the Alberta Weightlifting Association has resulted in empirical functions used to calculate the maximum weight lifted as a function of bodyweight. World record lifts establish these functions. (A cautionary note: because world records change, so do these functions.) The function for males is different from the function for females. The following notebook presents an exercise in using two quantities for the ranking metric: 1) total (i.e., snatch + clean and jerk) amount of weight lifted; and 2) the world record for the athlete's gender and bodyweight.

Ranking by the ratio of total to maximum weight lifted obviates both gender and bodyweight categories. Men and women can compete directly (with the caveats shown below) and without regard to bodyweight.

For now, the functions defining the maximum weights require that the athlete's gender is known. My hope is that one day a person professionally studying these metrics will find a replacement variable for gender.

The new system applied to a competition

I'm presenting a ranking based on the results of the 2018 IWF World Championships. See the Jupyter notebook for detailed results.

A few summary statistics for the top 20 lifters:

1. 5 are female and 15 are male.

2. The median bodyweight is 81 kg. The minimum bodyweight is 48 kg and the maximum is 169 kg.

3. There are 9 `upsets'. There are 10 bodyweight classes for each of the 2 genders, meaning that, by the original metric of total weight lifted, there are 20 first-place lifters. For the new metric, the top 20 lifters are populated by 11 of the first-place lifters and 9 of the second- and third-place lifters.

4. The cutoff `Sinclair fraction', or the ratio of total to maximum weight lifted, is 0.9580.

5. Differences in the Sinclair fraction can be quite small. The first and second lifters are separated by 0.0136, while the second and third lifters are separated by 0.000064. Someone who studies ranking metrics professionally should decide when to call these small differences a tie, and what metric to resort to as a second ranking. (Perhaps ratio of snatch to clean and jerk?)