Smith talks National weights
Grand National action
(Healy Racing Photos)
Trainer Ted Walsh appeared bemused by the rise of last year's third, which leaves him badly treated on official ratings with Tidal Bay, the top-weight on 11st 10lb.
Smith is allowed to use his discretion for the National in order to attract higher-class horses to take their chance in handicap company and he frames the weights himself, taking into account various factors.
"He's carrying 11st 2lb this year - the last four winners have carried 11st plus - and he was third last year. Horses have a very good record coming back a second time, and I thought he had a reasonably good chance," Smith said.
Referring to Tidal Bay, he said: "The horse's real rating is 171 and he has achieved that twice this year in the Hennessy and in the Lexus.
"In this race he is going to run off 162 and the theory behind it is that if he can replicate his Lexus run, he has got a chance of winning. The problem is, it's a completely different race.
"It's four and a half miles over 30 fences. If I'd left it as it is, he'd probably have to perform to 180 to win it but he's a 12-year-old and I don't think anyone would believe he could perform to that level. So I've compressed his weight, and some of the other horses at the top, in order to give them a chance of winning."
It appears a strong contest once again, with dual Ryanair winner Albertas Run next in on 11st 8lb, and 2010 Cheltenham Gold Cup hero Imperial Commander on 11st 6lb.
"It's great for the race as the top three have won 10 Grade Ones between them," Smith said.
"We are always talking about wanting high-quality horses to run and set the high standard the race deserves. We've definitely got that this year with Tidal Bay, Albertas Run and Imperial Commander.
"In Imperial Commander, I never thought I'd have a Gold Cup winner that wasn't top or second top weight. Who's to say how good he is, because we've only seen him race once in the last two years."
Smith said three horses had given him trouble as he made his decisions.
"Imperial Commander was one, as his comeback run wasn't anything like as good as I thought he was capable of achieving," he said.
"The job of the handicapper is to provide a puzzle which is difficult for the public to solve, and hopefully I've done that with him.
"The others were unusually further down the weights in Wyck Hill and The Rainbow Hunter. Wyck Hill won a race at Ascot some time ago which looked a nothing race at the time and I only put him up 4lb but the second horse Katenko has gone onwards and upwards and I've had to put Wyck Hill up twice while standing in his box.
"The Rainbow Hunter is almost a carbon copy. He was pulled-up on his most recent run, but the second, third and fourth from his last win have all won since."
Last year's winner Mick Kinane features among an elite group of ex-jockeys confirmed for the third running of the John Smith's Aintree Legends Charity Race on Grand National day.