With the changes to the cover and the material used in the core, and individual variation, there's not an easy way to compare. If you happened to have a pile of 2014 balls, I'd just use them and then get fit for whatever version was out when your supply was diminished. With my 2016 white Pro-Vs and my 2018 Pro-Vs Yellow, I may not be in the market again until the 2022 version.