Just 12 greyhounds remain in the running for the 2016 William Hill Greyhound Derby and the Racing Post's Jonathan Kay gives his verdict on both semis.He joins Sam Norris to preview all eight races on a superb card at Wimbledon on Saturday night that culminates in the two Derby semi-finals.Before that, we have heats for the William Hill Champions Hurdle and the William Hill Derby Plate and Jonathan offers his tricast and outright picks for all three competitions.Enjoy.