Sony recently launched My PS4 Life, personalized videos highlighting the games people played and the trophies they won in 2018. But, one Reddit user said they reveal more information than Sony probably intended.

Thanks to a bit of math, My PS4 Life videos can reveal the total number of people who’ve played a game, according to Reddit user Gamstat. That’s because each video shows the exact number of players who’ve received a trophy. Combine that with the percentage of people who obtained the trophy (which is available for every game via the PlayStation website) and you can apparently estimate the total number of players in the game.

Gamstat uses “Fallout 76” as an example. About 33,764 players earned the Photo Bomber trophy in that game, he said, and 8.3% of all players got that trophy. “Simple math: the total number of people who have played ‘Fallout 76’ on PS4 = 33,764 * 100% / 8,3% = 406,795,” he said.

Using this formula, Gamstat has figured out the player counts for about 98 titles so far and posted them to a website. The frontrunners will probably surprise no one. “Grand Theft Auto V” has about 51.7 million players on PS4 worldwide, according to Gamstat’s calculations. Vehicular soccer game “Rocket League” has 22.6 million. Human soccer game “FIFA 19” has about 12.5 million, but that’s apparently down from the 32.5 million who’ve played “FIFA 18.” Similarly, “Call of Duty: Black Ops 4’s” player count is down (9.2 million) compared to “Call of Duty: WWII” (24.6 million) and “Call of Duty: Ghosts” (12.6 million).

These figures are probably more estimate than hard fact, however. In an interview with Eurogamer, Gamstat explained many of the numbers are region specific and don’t take into account games with multiple editions that might have differing sets of trophies. They’re also taken from a specific time window, probably between Nov. 20 and Dec. 4. That means games released in the last week or two won’t be represented. The player counts also say nothing about a title’s concurrent players or total sales.

Variety reached out to Sony to confirm whether or not Gamstat’s figures are accurate, but it did not immediately respond.