Derby 1. Constitution River Timeform rating: 124p. Derby odds: 6-1. Trainer: Aidan O’Brien. Pedigree: Wootton Bassett x Chuppy (Le Havre) There’s no doubt about the “wow” performance of trials season: tactical speed, balance and a finishing kick, Constitution River had it all in a seven-length rout for the Dee Stakes at Chester, with a big timefigure to back up the form. But when was life ever that simple? An entry over a mile at Royal Ascot hints at stamina doubts, and current thinking seems to be leaning towards the 10-furlong French Derby on 31 May. 2. Benvenuto Cellini Timeform rating: 118p. Odds: 5-2. Trainer: Aidan O’Brien. Pedigree: Frankel x Newspaperofrecord (Lope De Vega) You could drive yourself mad trying to second-guess the pecking order in O’Brien’s long list of Classically bred colts, but he always sends a leading prospect to the Chester Vase and this year’s winner was just as impressive as Lambourn, who completed the Chester/Epsom double last year.…