The In Play Tennis Calulator (IPT-Calculator) is a program that calculates the chances for a player to win a tennis match at any stage during this match. The program uses a percentage for each player to win a point at their own service (WOS) as basis. This percentage can be inputed but can also be calculated using the strength (read odd) of the player. This free program is quite simple in use. It doesn't interpretate, it just calculates. The program can be used by punters (betters) to determine the odds, but also by bookmakers to help them calculate odds to offer on their website.