Valve has posted some interesting stats for Left 4 Dead 2's mutation modes. The team has been watching you closely as you work your way through the zombie hordes, and it turns out you like realism and gore in your L4D games: Realism Versus and Chainsaw Massacre have been the two most popular mutations by far, with Realism Versus (which was later turned into a permanent mode) grabbing 41 percent of the player base during its featured week and 22 percent of the playing time. The Chainsaw mode was the "most tried" of the mutations, with 52 percent of the player base revving it up, and 14 percent of player minutes spent playing it.
Outside of mutations, versus and the co-op campaign actually both nab about 40 percent of players every day. And while Valve doesn't mention any of the least-played mutations, it does give notice to the Infected-doubling Hard Eight mutation, which was only tried by 26 percent of players but still grabbed over 10 percent of that week's playing time. This week, it's a "Gib Fest," with everyone on the team getting M60s and unlimited ammo. That sounds like a hunting accident just waiting to happen.