A double occurs in volleyball when a player, during a match, is credited with scoring at least ten times in one (or more) of five statistical categories: aces, kills, blocks, digs, and assists. The term was apparently derived from similar basketball jargon; the expression "triple-double" was coined by former Los Angeles Lakers public relations director Bruce Jolesch in order to showcase Magic Johnson's versatility.[1]
There are four main types of doubles:
Of the five statistical categories, double digit match totals are most common for assists, but rare for any positions other than setter. The next most frequent double-digit category is digs, which is most often attained by liberos or defensive specialists, but can be achieved by any strong defensive player. Kills are the third most common double-digit achievement category, occurring predominantly among hitters, especially outside hitters and middle blockers. Likewise, double-digit blocking numbers are preponderantly accomplished by middle blockers or outside hitters, but are much less common than double-digit kills. Rarest by far are double-digit aces, which even the most exceptional server is unlikely to attain once in a career.[2][3][4][5][6]