Also MAC stands for Midair Attitude Correction, a maneuver in which a frisbee player changes the direction or speed of a throw without catching it. The basic MAC is to brush the side of the disc as it goes past you, so that your hand is moving with the spin. If you hit the disc a little bit forward of the middle, then the disc will now be moving away from you with roughly the same amount of speed and spin. Be careful about which way the spin is going. If you hit the wrong side of the disc, it will just drop straight to the ground.

MACs are legal in Ultimate frisbee games only if you MAC it to another player. If you MAC it to yourself, it's a travel.

If you can get a bunch of people who can all MAC it pretty well, you can form a MAC line, where instead of hitting the disc ahead of the middle of the disc, you just try and brush the back of the disc as it goes past you, in such a way as to increase the spin, and maybe to point the disc up a little more, so that it will go onto the next person, who MACs it to the next person, and so on. If you are on a frisbee team that can form MAC lines with any kind of regularity, you are bad-assed. MAC lines are hard.

Another style of MAC is to brush and push the disc forward as you are about to catch it. Basically if you see a disc floating down towards you, if you MAC the back of the disc, you can cause the disc to move farther forward. Another way to accomplish the same thing, but without MACing it in the strictest sense of the word, is to hit the bottom of the disc directly in the center with one of your fingers. If you hit it right in the middle, you won't take any spin or momentum off the disc, but the disc will now be higher and will float a few feet farther.