 The 2015 tournament involved twenty nations competing over six weeks . There were two stages , a pool and a knockout . Nations were divided into four pools , A through to D , of five nations each . The teams were seeded before the start of the tournament , with the seedings taken from the World Rankings in December 2012 . The four highest @-@ ranked teams were drawn into pools A to D. The next four highest @-@ ranked teams were then drawn into pools A to D , followed by the next four . The remaining positions in each pool were filled by the qualifiers . 
