An absolutely fascinating study into Steam by Ars Technica has unearthed some interesting information, including the estimation that 37 percent of all games purchased on everyone's favourite digital gaming platform remain unplayed.

The site has been randomly searching through 172 million Steam Community IDs for over two months to provide the fuel for its results.

Steam might be a platform for thousands of titles, but two games dominate the rest, and both are free-to-play: Dota 2, with an estimated 25.9 million owners, followed by Team Fortress 2 with 20.3 million.

In third is Half-Life 2: Lost Coast with 12.77 million, and then the rest of the top 20 is almost exclusively the domain of Valve's own titles: Counter-Strike: Source, Half-Life 2: Deathmatch, Left 4 Dead 2, Counter-Strike, Half-Life 2, Portal, Counter-Strike: Condition Zero, Day of Defeat, Deathmatch Classic, Ricochet, Counter-Strike: Global Offensive, Day of Defeat: Source, Portal 2, and Half-Life 2: Episode One.

The only non-Valve games in the most played list are The Elder Scrolls V: Skyrim at 14th, with 5.94 million owners, Civilization V at 16th with 5.84 million, and Garry’s Mod at 18th with 5.35 million.

There's a huge difference between owned and played, however: 2.1 million have actually played Half-Life 2: Lost Coast, compared to 10.7 who haven't. While Dota 2 and Team Fortress 2 remain top dogs overall, when looking at the most played games on Steam, titles like Modern Warfare 2, Warframe, Terraria, and Borderlands 2 all creep into the list.

So...how many games are in your pile of shame?

For more results from this incredible survey, check out the rest of the original Ars Technica report.