Contributor ranking in Discogs (part 1)

In Discogs you can get points for every contribution. There are a few people who have made it a sport to score as many points as possible, the so called "rank hunters" which some people look down on for reasons that I do not understand (in case you want to be a rankhunter or you want to be a more effective one, please check out the "Unofficial Discogs rankhunting guide" to maximize your efforts).

It works like this: adding a new release gets you three points and each edit (regardless how much you edit) gives you one point and there is some sort of leaderboard/ranking for all contributing users to Discogs. There are a few people that have an enormous amount of points and who seem to live for the site. The number one currently has over 356,000 points.

When looking at the graphs they really reminded me of power laws, and the 80/20 rule because when looking at the first page of the contributors in Discogs and power law pictures there is a striking resemblance so I thought it was time for some unscientific statistics.

I grabbed the rank data of the top 1000 contributors in Discogs by scraping, as Discogs doesn't make this information available easily. Because Discogs has anti-scraping measures in place I probably didn't get all the correct information and missed a few contributions here and there.

For each user I extracted the points for each user and computed the percentage of the total amount of points for the user. I also computed it for every 50 contributors (like Discogs does on each page) and also computed the cumulative percentage of the top X (in batches of 50).

The numbers for the top 10 of contributors (percentages only):

1. 1.12%
2. 0.93%
3. 0.76%
4. 0.68%
5. 0.51%
6. 0.50%
7. 0.45%
8. 0.44%
9. 0.44%
10. 0.41%

which is not very interesting, except showing that the number one has almost 3 times as many contributions as the number ten.

It gets much more interesting when looking at the numbers per batch of 50:

• 1-50: 18.22%
• 51-100: 10.53%
• 101-150: 8.49%
• 151-200: 7.23%
• 201-250: 6.12%
• 251-300: 5.34%
• 301-350: 4.82%
• 351-400: 4.42%
• 401-450: 4.08%
• 451-500: 3.77%
• 501-550: 3.52%
• 551-600: 3.28%
• 601-650: 3.08%
• 651-700: 2.85%
• 701-750: 2.67%
• 751-800: 2.54%
• 801-850: 2.42%
• 851-900: 2.30%
• 901-950: 2.21%
• 951-1000: 2.11%

As can be seen the contributions very quickly taper off and then seem to get less at a much lower pace (the start of the "long tail"?). Looking at the accumulated percentages is more interesting:

• 1-50: 18.22%
• 51-100: 28.74%
• 101-150: 37.23%
• 151-200: 44.46%
• 201-250: 50.59%
• 251-300: 55.93%
• 301-350: 60.75%
• 351-400: 65.17%
• 401-450: 69.25%
• 451-500: 73.02%
• 501-550: 76.54%
• 551-600: 79.82%
• 601-650: 82.90%
• 651-700: 85.75%
• 701-750: 88.42%
• 751-800: 90.95%
• 801-850: 93.38%
• 851-900: 95.68%
• 901-950: 97.89%
• 951-1000: 100.00%

The top 25% contributors account for slightly more than half of the points and the top 60% for almost 80% of the points.

That is not really the 80/20 distribution but I only looked at the top 1000 contributors out of more than 406,000. To be more correct I should actually look at the points of the top 80,000 contributors but as said Discogs is not making that easy for me to access that information. In the next few days I will try to crawl more information and come back with hopefully more interesting results.