NBA Kirkland asked me via Twitter to post my spiel about achievement rarity on True Achievements somewhere, so here it is.
This is going to be particularly relevant given the new achievement rarity functionality being added to the next Xbox One update, just announced on Major Nelson's podcast (~ 27 minute mark). Takeaways from the announcement:
- There will be a new notification for rare achievements
- There will be a statistic showing the number of rare achievements you have unlocked
- Achievements will be classed as rare in some way based on the entire Xbox population
Here's what I wrote for episode 38 of Zed to Zed::
The issue was nothing to do with storage. Rich said that they couldn't think of a way to include this information without making TA more confusing; TA already has the TA score which is confusing enough for newcomers, and it was felt that adding another statistic on top of TA and the TA ratio wouldn't work well.
The storage issue was related to the idea of storing everybody's stats (as in, every single gamertag, ever), but this wouldn't be required if TA was able to just query raw rarity figures for each achievement. The additional storage would be relatively neglible (an extra field or two per achievement, alongside title, gamerscore, etc).
I personally would love to revisit this; I'm certain that it could be added in a way that didn't burden the site or increase overall complexity, and I'm also certain it would be a very popular statistic.