Interesting. So are 2016 rio olympic balls for example the same size as the slightly larger international balls?
edit: I believe it's this ball, but I'm not sure what "size 5" means or if all "size 5" balls are exactly the same size: https://www.amazon.com/Mikasa-MVA200-2016-Olympic-Yellow/dp/B001F51TYK/ref=sr_1_1?ie=UTF8&qid=1485032149&sr=8-1&keywords=mikasa+rio+2016