Valve Shuts Down New Way of Estimating Game Sales On Steam (arstechnica.com)

A recently discovered hole in Valve's API allowed observers to generate extremely precise and publicly accessible data for the total number of players for thousands of Steam games. While Valve has now closed this inadvertent data leak, Ars can still provide the data it revealed as a historical record of the aggregate popularity of a large portion of the Steam library. From the report: The new data derivation method, as ably explained in a Medium post from The End Is Nigh developer Tyler Glaiel, centers on the percentage of players who have accomplished developer-defined Achievements associated with many games on the service. On the Steam web site, that data appears rounded to two decimal places. In the Steam API, however, the Achievement percentages were, until recently, provided to an extremely precise 16 decimal places.

This added precision means that many Achievement percentages can only be factored into specific whole numbers. (This is useful since each game's player count must be a whole number.) With multiple Achievements to check against, it's possible to find a common denominator that works for all the percentages with high reliability. This process allows for extremely accurate reverse engineering of the denominator representing the total player base for an Achievement percentage. As Glaiel points out, for instance, an Achievement earned by 0.012782207690179348 percent of players on his game translates precisely to 8 players out of 62,587 without any rounding necessary (once some vagaries of floating point representation are ironed out). Ars has shared the Achievement-derived player numbers in their report; there's also a handy CSV file. Some of the titles with the most total unique players include Team Fortress 2 (50,191,347 player estimate), Counter-Strike: Global Offensive (46,305,966 player estimate), PLAYERUNKNOWN'S BATTLEGROUNDS (36,604,134 player estimate), Unturned (27,381,399 player estimate), and Left 4 Dead 2 (23,143,723 player estimate).

Comments

Not so rare after all

[Typing_Ptarmigan]

So more than 2.5 million other TF2 players also have my "rarest" TF2 achievement. And more than 50 million other TF2 players apparently think the weapons I'm trying to sell are overpriced. On the bright side, there must be approx. 12.5 million spies to burn up.

Re:Not so rare after all

[Carewolf]

Those numbers are how many have "bought" the game. So life-time total of downloads. Not all of them might have even launched it, or launched it the last 10 years.

Re:Not so rare after all

[hairyfeet]

Exactly, I have nearly 200 games in my Steam library, I've played....maybe 12. Most of them I've downloaded once, backed them up to my external drive, and then promptly forgot about them because I don't have the hours to play them all.

This is the problem game devs are gonna find with more and more playing MMOs as once you've sunk some serious time into a MMO game you like? You have a limited amount of hours in the day and many will just go play the game they have already invested in.I keep buying games because I'll see something that looks interesting in a Humble Bundle or on a Steam sale but when it comes time to actually play it? i just end up going back to my MMO.

The question everyone's asking

[Anonymous Coward]

What the hell is Unturned?

Re:The question everyone's asking

[The Raven]

It's a zombie survival game, cartoonish graphics but well designed, in the style of the DayZ mod. Free to play, with $5 buy in to gold servers (essentially a fee to avoid more rampant cheating) and cosmetics.

Not particularly amazing or awe inspiring, but well made and with a huge young-player following. Parents don't ban it because it's so non-threatening looking with it's lo-fi cartoonish graphics, though the gameplay is the usual find or craft guns, kill zombies, and kill your fellow humans if you think they looked at you funny.

The interesting thing is that it's pretty much the work of a single dev... a kid who started work on it at around 14 or 15, and who I suspect is a millionaire already, though I don't think he can drink yet. What's the drinking age in Canada?

Steam, the next Flash or Java

[Anonymous Coward]

Steam will become crux of the gaming community with privacy violations and security holes.

Re:woohoo!

[Anonymous Coward]

You named your dogs Bruce and Eric?

Weird. That's just cruelty.

Re:Divide two floats and store the result as doubl

[Cajun Hell]

You have to admit, nobody would ever do that.

Re:Without reading tfa

[GrimSavant]

At this point, I basically assume that everyone who brings up the term "SJW" unprompted and unironically is a shithead.

I wonder how good my odds are on that guess. Because it seems like an obvious path to troll or display a defensiveness towards socially undesirable behavior. I don't see how this sense of victimhood could more likely than not be the result of a healthy rational thought process.

Factors?

[Unnamed Chickenheart]

"an Achievement earned by 0.012782207690179348 percent of players on his game translates precisely to 8 players out of 62,587 "

8 players out of 62,587

Or 16 players out of 125,174

Or 32 players out of 250,348

Etc.

Unless I'm missing something (I'm no mathgician) you can not tell which, if any, common factors in player base and players with an achievement have been truncated?

Re:Factors?

[Calydor]

As the summary said, when you have multiple achievements with different values, you very quickly come to a point where there is only one X that fits all the equations.

If another achievement has been completed by 127 players, and the most common one is done by 59,993 players, you quickly run out of possibilities. Sure, there MAY be another result in the billions of players, but that's like GPS - all GPS calculations have TWO solutions to the equation, but one solution is on the planet's surface while the other is in outer space.

Re:Factors?

[91degrees]

Surely there will always be x, x*2, x*3 and so on as possible solutions. I guess when you get enough of these achievements, the odds of all of them having the same multiple becomes less likely, but there are also a lot of games, so at least some will have these anomalies.

Re:Factors?

[GrimSavant]

Adding a bunch of achievements that aren't gimmes in either direction seems like it would help narrow the possibilities a lot, and more opportunities to have primes show up to simplify things. Presumably they just used the lowest number that is consistent with the ratios and common denominators, since if you have enough achievements with effective noise around the number of people who achieved it then that cuts down on the chance that the higher harmonics are the real values.

Or they could have done a short term time lapse, and used the changes in numbers over period of time with a more controlled number of sales and achievements gained to try to sift out the results with a small longitudinal dataset. That seems like you could do some sort of anti-aliasing like effect to filter out or at least mitigate the trouble cases.

Really??? I must be missing something.

[Sqreater]

Sixteen digits after the decimal? Have they overturned significant digits?

Re:Really??? I must be missing something.

[tlhIngan]

Sixteen digits after the decimal? Have they overturned significant digits?

No, they haven't.

If the number of players is X, and the number of total players is Y, then when you divide, X/Y, the number of significant figures is actually infinite as both are "exact" counts. You can't have 3.1 players, for example, so there's no uncertainty digit. You have 3 players exactly. Likewise, there are a total of 10 players. Both values have infinite precision because they are exact values .

Significant figure rules apply when you have an uncertainty digit, like something takes 5.2 seconds to accomplish. In this case, the .2 is an uncertain digit but reflects the general system of precision we can get out of human timing. (The actual time may be 5.5 seconds, which is within the uncertainty digit).

Re:Not an SJW article???

[MrL0G1C]

You're obsessed. And apparently, you don't like justice. What is it about people who use the term SJW and rail against it?

Re:Without reading tfa

[MrL0G1C]

People who obsess about SJWs are living in their own reality bubble, a bubble kept in place by right-wing media for the benefit of corporations and the super-rich.