In most cases, throwers will have a pivot established when they make their throw. The rules do, however, allow for a throw before the third ground contact without a pivot, assuming that there's no change of direction, no acceleration, and that your last point of contact was the playing field proper. What happens, however, when a disc is thrown out of bounds, and can not be caught in bounds, but can be caught by a player whose last point of contact is in bounds? In these rare instances, an offensive player has the option, given the right circumstances and an appropriate amount of athleticism and field sense, to jump, catch the disc, and throw it back in bounds all before landing (I think that macking is allowed in conjuction with the greatest). As long as their last point of contact is in bounds, and they release the disc before contacting the ground again, the disc is still considered "live" and in play. If an offensive player catches the disc, the offensive team will retain posession. Likewise, if the greatest is attempted in the wrong endzone, since the disc is still "live" a defensive Callahan could result. A successful greatest is one that is caught by another player on the offensive team, which in turn means that possession is retained. The greatest is called the greatest because it is, possibly, the most exciting play in ultimate. In the above picture, many of the characteristics of a greatest are present. While the field boundaries are not in the picture, the player in red is in the air, and a foot or two off of the field. In this case, they are out of the side of the endzone that they are attempting to score in, their back is to the field, and as is common in many greatest attempts, they are throwing a push pass (thumb down grip) that is intended to go in the direction that they just came from. The sideline player in black (on the left) is looking at the side endzone line to ensure that the player actually left from in bounds. Since there are people watching the game, you can see that the player is quiet close to them.