Achievement tracking on Steam shows that only 0.2% of PC players survived all campaigns on Expert.
Valve's Left 4 Dead figures show how gamers have been getting on thanks to Steam's stat tracking abilities.
While no achievement has been earned by all players, there are a few around the 70 per cent mark.
'DRAG AND DROP' which tasks players with rescuing a survivor from a Smoker's tongue before he takes damage has been earned by 72.7 per cent of PC players and is the most earned achievement. 'BRAIN SALAD' - making 100 headshot kills is the second most earned achievement with 69.4 per cent of players seemingly able to point a gun in the face of oncoming zombies.
The hardest achievements to earn are unsurprisingly 'LAMB 2 SLAUGHTER' - As an Infected, incap a Survivor who has entered and left a safe room, and 'ZOMBIE GENOCIDEST' - kill 53,595 Infected. No PC gamer has managed to earn these achievements.
You'll find the full list of Left 4 Dead achievement stats over on www.steampowered.com.