Xbox gamerscore, achievements and playtime
Xbox counts your progress in points rather than in trophies, and it reports how long you played most of your games. This guide explains what gamerscore actually measures, where the hours come from, and why a few games have none.
What gamerscore is
Every Xbox achievement is worth a number of points set by the game's developer. A standard retail game has 1000 points to earn, and most add-ons add more. Your gamerscore is simply the sum of the points of every achievement you have unlocked, across every game, since your account was created. It never goes down.
On your card, EveryGameStat shows the gamerscore you have earned per game against the maximum available for that game, so you can see that you have 450 of 1000 in one title and 1000 of 1000 in another. The card total is your overall gamerscore.
Where the Xbox hours come from
EveryGameStat reads Xbox through the OpenXBL service, which returns your games, achievements, gamerscore, recent activity and, for most titles, the minutes Microsoft has recorded for you. Those minutes are what you see on your card and in your library.
Not every game reports them. Some older titles and some apps come back without any figure at all, and Microsoft occasionally returns a partial answer where a title that normally has hours temporarily has none. In those cases the field stays empty. It is never filled with a zero, because a zero would claim you never played the game, and it is never estimated from achievement dates. A stored figure is also never overwritten by a lower one, so a bad answer from the API cannot wipe out hours you really played.
How linking works
Link Xbox with your gamertag. The site looks up the public profile behind it and imports your games and achievements. Your privacy settings on the Xbox side control what is visible: under Privacy and online safety, the settings for "Others can see your game and app history" must allow everybody, or at least not be blocked, for the game list to come through.
What counts as a game
The Xbox API returns everything that has awarded achievements, which includes PC titles played through Game Pass and the Xbox app on Windows, and older Xbox 360 games. Apps without achievements do not appear. Games you played on someone else's console under your own account do count, because achievements belong to the account.
Rare achievements
Xbox marks achievements as rare when fewer than about 10% of players have unlocked them and shows a diamond icon for those. The API includes the unlock percentage, so on the game page the rarest achievements come first, the same way they do for Steam.
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