when did tennis balls changed from white to yellow
Tennis ball Modern tennis balls must conform to certain criteria for size, weight, deformation, and bounce criteria to be approved for regulation play. The International Tennis Federation (ITF) defines the official diameter as 6.54–6.86 cm (2.57–2.70 inches). Balls must have masses in the range 56.0–59.4 g (1.98–2.10 ounces). Yellow and white are the only colors approved by the ITF, and most balls produced are a fluorescent yellow known as "optic yellow", first introduced in 1972 following research demonstrating they were more visible on television.
Australian Open The Australian Open is a tennis tournament held annually over the last fortnight of January in Melbourne, Australia. First held in 1905, the tournament is chronologically the first of the four Grand Slam tennis events of the year – the other three being the French Open, Wimbledon and the US Open. It features men's and women's singles; men's, women's and mixed doubles and junior's championships; as well as wheelchair, legends and exhibition events. Prior to 1988 the tournament had been played on grass courts, but since then two types of hardcourt surfaces have been used at Melbourne Park – green coloured Rebound Ace up to 2007 and, afterwards, blue Plexicushion.[1]