Upcoming and Results page refactoring. If you are unfamiliar with the term "refactoring", it means restructuring/redoing something without changing the existing functionality. So those pages work the same way as they did before, but a lot have changed under the hood. Those pages should be waaaay faster than before. Filtering is done on the client side also Results page preloads the first 50 tournaments to display results as fast as it can.
New badges. Who on Earth doesn't like badges, right? The North American Championship happened and some of our users are getting one year old as well :D Also did you know: After every 20$ donation given (over time), you can design a badge on ABR.
ABR API documentation. Here you go. You are free to use these endpoints in your projects, sites, apps, whatever. I only ask that you refer back to my site.
Faction charts on tournament pages. You can filter for factions or IDs on the chars.
Facebook importing also saves cover image. It is so easy to get event data from Facebook to ABR. It imports title, date, location, description and even guesses tournament type.
Multiple day tournaments. You can either have a single day, multiple day or a recurring event.
Various bugfixes and minor improvements. You can check github if you are interested.
Oh, and I almost forgot: I wrote an article on the Rotation and Revised Core. (This was before the new MWL/ban/restricted list)