Issue link: http://itf.uberflip.com/i/1169625
22 • ITF Global Tennis Report 2019 What we've learnt: performance HOW PERFORMANCE DATA WAS COLLECTED The data presented in the performance sec on of each of the Na onal Associa on reports was developed using rankings and tournament data from the comprehensive ITF results database. The aim was to describe the rela ve performance of na ons in the area of player development. 12 variables describing a na on's professional playing base and depth, representa on in Grand Slam tournaments, and track record in conver ng junior players into professional players were established. By using tournament data from the ITF results database, we were able to produce for each Na onal Associa on an accurate account of junior and professional player performance during 2017. Junior players are defined as those boys and girls who held an ITF Junior Ranking between 1 January and 31 December 2017. Professional players are defined as men and women who held an ATP or WTA ranking between 1 January and 31 December 2017. Where a player held both a junior ranking and a professional ranking within this period, they are included in the respec ve variables. If a player competed in both a junior Grand Slam tournament and a professional Grand Slam tournament during 2017, they are included in the respec ve variables. The performance sec on of each Na onal Associa on report presents that country's tennis landscape in six key areas, across the established 12 variables: Ranked players • Total number of players ranked • Players ranked in Top 250 • Players ranked in Top 100 Grand Slam tournament representa on • Main draw representa on • Qualifying draw representa on Professional ranking by age • Professional players in Top 500 by age Junior to professional ranking conversion • Conversion rate (%) • Conversion speed (weeks) Junior player ranking conversion to junior Top 100 • Conversion rate (%) • Conversion speed (weeks) Professional player ranking conversion to Top 100 • Conversion rate (%) • Conversion speed (weeks) The performance reports give each na on a global ranking for each variable. A na on's outcome in each variable is reported rela ve to the top ranked na on globally. The reports also provide Na onal Associa ons in Tier 4 only with comparisons with other Tier 4 na ons for each performance variable. These comparisons are calculated by using the same points of reference as in the par cipa on reports: a er mid-point, a maximum value and a series of percen les (see page 10 for more details). These comparisons were not provided for Tiers 1 to 3 due to limited data for the na ons in these ers. A full explana on of ITF Eligibility Tiers is provided in Appendix H page 561.