Valve API Briefly Leaks Player Counts For Over 10,000 Steam Games

Last week, Valve revealed it was working on a way for developers on its Steam storefront to have better access to player and sales numbers as a way to let them make more informed decisions. This week, we caught a brief glimpse into how much data Valve might actually have at its disposal.

Ars Technica reports that Valve's API, which organizes much of its information into a digestible format, was recently found to have a hole in its security that let common observers to gather very accurate data about how many players individual games on Steam had accrued.

While the numbers drawn from the API are extremely accurate, they don't account for every game; the parsed API uses developer-created achievements to reverse-engineer the number of players for a given game, which means only games with achievements (about 13,000 of the 23,000 games on Steam, according to Ars) show visible numbers. Though it's an incomplete data set, its numbers are the most accurate data we've seen for Steam games yet - more accurate than the old Steam Spy numbers.

Though the hole was quickly patched by July 4, Steam Spy creator Sergey Galyonkin shared his numbers for the top games on Steam with Ars, giving players, developers, and everyone else a look at how big some of these numbers go.

The Steam game with the highest number of total players (again not counting games without achievements, such as Valve's own Dota 2), as of July 1, is Team Fortress 2, with over 50.1 million total players. Following closely behind is Counter-Strike: Global Offensive (46.3 million), Playerunknown's Battlegrounds (36.6 million), Unturned (27.7 million), and Left 4 Dead 2 (23.1 million).  For the full breakdown, check out Ars' article on the topic.