Horatio Nelson Derby Plunge Aidan O'Brien's Horatio Nelson has been the subject of a massive ante-post gamble for the Vodafone Derby forcing bookmaker William Hill to first cut his odds to 7-1 from 9-1, then to 11-2 and finally to 9-2 as the money kept rolling in. Elsewhere on the Derby, as a direct consequence of the gamble on Horatio Nelson, William Hill have pushed the Dante winner Septimus out from 7-2 to 6-1. O'Brien's two other possible Derby runners Dylan Thomas and Mountain are available at 12-1 and 66-1 respectively. Tony Kenny William Hills Irish spokesman said ' 'From just after 9 o'clock this morning there was only one horse the punters wanted, they took all of the 9-1, 7-1, 11-2 on offer and then forced us down to 9-2, half the price he was this morning.' He continued 'With O'Brien's four having their final gallop this morning, the dramatic move for Horatio Nelson could be a biggest non-verbal sign that Kieran Fallon has decided who'll ride in this Saturday's feature at Epsom'William Hill can also report strong interest in Ballydoyles only runner in Friday's Vodafone Oaks, she was shortened today by Hills from 10-3 to 3-1.Vodafone Derby: 6-4 Visindar , 9-2 Horatio Nelson (from 9) 6-1 (from 7-2) Septimus, 8-1 Sir Percy, 12-1 Dylan Thomas, Papal Bull, Lindas Lad, 14-1 Hala Bek, Papal Bull (from 16), 16-1 Atlantic Waves, Championship Point, Olympian Odyssey, 25-1 Best Alibi, 40-1 Art Deco, 66-1 Dragon Dancer, Mountain, 100-1 Youmzain, 150-1 Altius, Before You Go, 200-1 Sixties Icon, Snoqualmie Boy, 250-1 Sienna Storm, 1000-1 Noddies WayVodafone Oaks: 3-1 (from 10-3) Alexandrova, 4-1 Short Skirt, 9-2 Galatee (from 5-1), 11-2 Riyalma, Speciosa, 7-1 Scottish Stage, 8-1 Time On, 16-1 Guilia, 33-1 Queen Cleopatra, 50-1 Rising Cross, 66-1 Kushnarenkovo, Souvenance, 100-1 Kassiopeia, Kaylianni, Prowess, Rajeem