Even though he said the next one is going to be .52a, .53a, etc, I think version numbers should be determined by the number of updates as well as how gamechanging the update is. For example, if starfarer right now were 1.0.0, this update might be called 1.1.0 due to a totally new game system being added, Ship Systems. Smaller updates might be ship balances (like the Conquest balances in .52a) and Admiral AI changes. Large gameplay changes, such as the introduction of Campaign, might deserve higher second-degree numbers. The first number, in my opinion, should not be changed unless the game goes past 10 major updates (and I mean major, like campaign-size additions/changes or otherwise) or the game advances into a stage, e.g. from Alpha to Beta stage. A forth number can be added, or a letter for this game's case, if anything's small enough.