Unfortunately, all new players will soon figure out how important these squares are. Because of the great advantage that the corners bring, both players will try to get there first. One way to use mobility to your advantage is to keep your pieces in between pieces of your opponent and to gradually try to run him or her out of good moves, forcing yourself into a corner. Mobility can be used in many ways to the player's advantage, but without good availible moves, a player can be forced by a good opponent into a loss. Another key reversi concept is that of parity .
Parity essentially means moving last in a closed area of play.
For example, if there are only two spaces left on the board, the person who moves second, or has the parity, will gain more pieces than the first in that area. This can be expanded upon, as if there are four or even six open spaces in an area, the person who moves second will always have the advantage, as he or she will get the last move. Keeping parity in mind can help a person decide where to move next in order to keep a good position or in order to improve upon a bad one. Bearing this in mind, a person in a game that has one area on the board with five open spaces and a similar one with six should move into the area with five and utilize the advantage of parity. One way to help explain why parity can be so effective is by taking the concept of mobility into account.