This pop flash for coffins is extremely effective at flashing any and all terrorists attempting to run into the site. It is extremely difficult to dodge and has good coverage, hitting pretty much everything except pool.
Difficulty: 2/5
Importance: 3/5
Line up with the edge of this wall:
Then, turn around and put your crosshair on the top edge of this red line on the concrete, aligned horizontally with the house symbol on the upper concrete bag:
Then, jump and right click throw the flash. Result:
Note: The flashbang does go further out than the line would indicate; in fact, it pops wide enough to blind someone looking at coffins from CT.