http://i.snag.gy/QZI1M.jpg

every map has like black spots and some **** is weird

think your graphic card is dying

Or overheating, i used to get mad artifacts when this happened. Try opening the side of your case.

 opy
is right, ur graphic card is overheating, close some unnessesary programs when you want to play or play in lower ress & graphics.

just get a can of air and clean your computer.