My brother wants to know.

>Formula for accuracy and evasion The probability that a move will hit is calculated as follows: http://cdn.bulbagarden.net/upload/f/ff/Accuracy_calc.png Abase is the base accuracy of the move (in percent - e.g. a base accuracy of 95 is counted as 0.95), Accuracy is the current accuracy stat of the user (in percent - e.g. raising accuracy by three stages raises this number to 2), and Evasion is the current evasion stat of the target (in percent - e.g. lowering evasion by two stages lowers this number to 0.6). If P is greater than 1, the move will surely hit. In a 2-on-2 battle, it is possible for a move that hits two or three targets to miss some of the targets and hit others - the probabilities are calculated individually for each target.

~Bulbapedia