Correct, that is why the baffles help in the discharge velocity by helping to keep the air in the deck. One of the issues the baffle also helps with is the air turbulance between the chambers at the front of the deck when the blades pass each other. In those two areas the blades are passing each other in the opposite direction so while the blades are all spinning in the same direction when they pass each other the air flows are in the oppsite direction. The baffles help in limiting the size of this area to limit the turbulance. Blade placement also comes into play, too high and it can over pressure the deck and too low can cause too much air to escape under the baffle.