Boris Becker broke the world record for the fastest serve in a Davis Cup match in 2007 . The Croat was clocked at 156 mph ( 251 kph ) to beat Andy Roddick 's previous mark . Type 3 tennis balls were introduced by the ITF in 2002 , and are 20 % bigger in diameter . They are seen as a potential solution if the number of aces begins to increase .
Ivo Karlovic broke the world record for the fastest serve in a Davis Cup match in March . The Croat was clocked at 155 mph ( 251 kph ) to beat Andy Roddick 's previous mark . Type 3 tennis balls were introduced by the ITF in 2002 , and are 6 % bigger in diameter . They are seen as a potential solution if the number of aces begins to increase .