Here at Ars, we have a longstanding obsession with revealing the hidden numbers in the secretive world of video game sales and gameplay data. So we were intrigued this weekend when we heard that Sony seems to have inadvertently revealed the total number of players for a large majority of the PS4's library.

The leak centers on Sony's recent My PS4 Life promotion, which lets users generate a personalized statistics video for their PSN Gamertag. Amid some aggregate statistics and "total hours played" numbers for your favorite games, the video also lists your "rarest" trophy and, crucially, the precise number of PSN users who have earned that trophy.

Sony has long made public the percentage of a game's players that have earned any specific trophy on PSN (rounded to the nearest tenth of a percent). Combining that percentage with the "My PS4 Life" numbers, that makes it relatively simple to reverse-engineer an overall "players" estimate for that game.

Reddit user gamstat, who was among the first to notice this treasure trove of accidentally public data, summarizes the math: "Here, 33,764 players earned the 'Photo Bomber' trophy in Fallout 76. And on playstation.com it's revealed that 8.3% of all players got this trophy. Simple math: the total number of people who have played Fallout 76 on PS4 = 33,764 * 100% / 8.3% = 406,795."

This data extrapolation isn't without its issues. For one, the data seems to have been generated between November 20 and December 4 (based on player reports of trophy timing) and seems unlikely to be updated going forward. Data for some games is limited to the specific regions in which those trophies were earned, and trophies that are rounded to "0.1%" of users might not generate accurate player numbers. And the number of "players" being discussed here might not track precisely to the total number of "owners" across the PS4 ecosystem (possibly including completely offline players for disc-based games).

In any case, gamstat has expanded beyond Reddit and set up a separate website that currently lists the extrapolated PSN player counts for nearly 100 games, from Grand Theft Auto V (51.7 million estimated PS4 players) and FIFA 18 (32.5 million players) to, uh, VVVVVV (28,800 players). But that's just a small taste of the thousands of My PS4 Life videos that have been shared online with the handy #MyPS4Life hashtag.

Gamstat has downloaded as many of these videos as he can and collected a handy ZIP file of about 3,700 screenshots showing the relevant trophy data for various games. As those get converted to player counts, we should see data for a wide array of PS4 titles.

You might remember that Valve saw a similar leak of Steam sales data via Achievement percentages earlier this year. That came after the company took steps to shut down third-party sites like Steam Spy in favor of a still-nebulous "more accurate" version that would provide "official" sales statistics.

Until then, we'll constantly be on the lookout for new ways behind the game industry's usually opaque data curtain.