Cause there is wind. You may not have known that, but now you can see for yourself.
That there is the Buy a Life taunt, added during the Love & War Update. Spy, being the cocky dick he is, pulls out a wad of cash and flings it derisively while taunting his poor & Irish foes. It was the subject of the highest-rated screenshot I ever posted to Steam.
But what’s important is that the money always blows in the same direction! No matter what direction you’re facing, no matter how many times you crank the map up. It’s not randomized in any way; there’s actually some sort of map entity determining what direction the wind’s blowing. Testing has shown me that it’s usually in the direction of red spawn.
Tacoman_ is the self-proclaimed Source particle professional of SPUF, and he has this to say on the matter: “The particle system is made in a way in which it gets moved by ‘gravity’. So the particles will always blow in the same direction which is independent of the map being played on. The ‘standard’ initial movement for particles is along the X axis moving forward, this means that the particles should be getting swayed by the wind along the Y axis going backwards(negatives).” Thurbo adds: “You can map particle movement to things like the direction the parent object is facing if you want. You can even base movement off of how far away from the center of the world the particle system is created. Buy a Life particles aren’t mapped to anything, so their movement is always the same within the world xyz coordinates. So I am now suspecting that Valve messed up and actually intended to map the direction of the initial force to the direction of the taunting Spy.” So, now you know why!
Now, is there any possible way to gain a statistical advantage from this? After all, through racking my brain enough I’ve figured out tactical uses for sprays, cosmetics, friendly disguises, suicide (twice), horrible spies, novelty taunts, strange filters, and even straight downgrades. So there’s gotta be at least one way to use knowledge of the map’s wind currents for personal gain, right?
Nope. I literally cannot think of a single one.