In 2006, the US Open introduced instant replay reviews of line calls, using the Hawk-Eye computer system. It was the first Grand Slam tournament to use the system.[50] The Open felt the need to implement the system because of the controversial quarterfinal match at the 2004 US Open[citation needed] between Serena Williams and Jennifer Capriati, where important line calls went against Williams.[51] Instant replay was available only on the Arthur Ashe Stadium and Louis Armstrong Stadium courts through the 2008 tournament.