Counter-Strike: Global Offensive Heat Map/firing locations ^
"If you’re interested in how developers collect gameplay data and use that to improve their games, check out these heat maps Valve used to improve Counter-Strike: Global Offensive."
@Valve; Round off the corners and add window frames. Or invert the rounded corners and add window frames. Nope. Scratch that. Place portal turrets+god mode at every corner. I've just created CSQuake! Everyone will now run around having fun whilst not hugging a corner. :)
Seriously though it's pretty interesting info.