I-Formation: A system of positioning in doubles play in which one player lines up in front of the other; the forward player covers the front court area and the other covers the back court area.

In-Lawing: A common term used in the NFL, where an opponent sweet talks his opponent by saying something to the effects of, “Come on now, let’s not hurt each other too bad today, I won’t hit ya too hard and you won’t hit me too hard, let’s have a beer afterward brother.” It is all a ploy as the sweet talker never intends to play it “nice and soft.”

Inning: A round of play that permits the gain and loss of a serve by each side.

Jam Serve: A serve directed into your opponent’s body; forcing your opponent to move.

Journeyman: A type of individual that lacks natural talents, but makes up plenty with tremendous efforts and heart. For example, the great tennis journeyman, Brad Gilbert. He wrote a famous and instructive book called, "Winning Ugly."

Juicy: A guaranteed setup or an easy offensive opportunity to end a rally.

Jump: An advance technique where a player jumps to maintain center court position.

Kibitzer: To give unsolicited racquetball advice during a course of a game, from Yiddish-Russian.

Kill Shot: A shot that hits too low on the front wall to be retrieved before the second bounce.

Killer: A player, who tries unusually high percentage of kill shots, also calls a shooter or gunner.