Grand National 2016 runners and riders [Infographic]
Jockey Leighton Aspell could become the first jockey to win the Grand National three years in a row.
He is partnered once again with last year's winner, Many Clouds, in the world's most famous steeplechase.
AP McCoy believes Saturday's National has the best ever line-up but feels Many Clouds is the worthy favourite and will triumph again.
Ulster great McCoy - who retired last April at the age of 40 after 20 successive champion jockey titles and a record 4,358 winners - had to wait until his 15th attempt before finally winning the Grand National.
McCoy triumphed on Don't Push It at Aintree in 2010, becoming the only jockey ever to be crowned BBC Sports Personality later that year.
"It's a classy Grand National," McCoy said.
"There are a lot of good horses but Many Clouds (8-1) deserves to be the favourite - his performance (in winning) at Kelso (last month) was great and the one thing he does is he stays and stays and stays."
McCoy rode Shutthefrontdoor to fifth in his final Grand National last year.
So does he not fancy the horse that for a long time looked like it might take him to the fairytale career finale?
"Shutthefrontdoor just got a bit tired at the end last year having not run for a long time," he said.
"He was a bit disappointing at Newbury (last month). He had a few problems with his feet but he's had a better preparation this year.
"But it is a better National than for a long time with the likes of Paul Nicholls' Silviniaco Conti (10-1). Jonjo O'Neill's Holywell (14-1) is well handicapped and could win it.
"You can even look down at Sir Des Champs (40-1). If I could get Holywell up and over Becher's Brook I'd know if he had the bottle for it or not. That's the problem."
Many Clouds' jockey Leighton Aspell is delighted with the form of his mount as he looks to repeat last year's victory and become the first man to win the National in three consecutive years, having also ridden to glory on Pineau De Re in 2014.
"Kelso was enough of a test for Many Clouds," he said.
"It wasn't the easiest going as only seven days before it had been abandoned (due to waterlogging)."
Trainer Oliver Sherwood is confident about Many Clouds' chances in the £1million race.
"We are really happy with him," he said.
"Kelso was pretty much automatic gear for him. He's pretty fit. It's just a question of keeping him mentally straight. We'll take him over some fences as part of the build up. We are very happy with him and feel he's coming right at the right time."
Meanwhile, Tom Scudamore is keeping his fingers crossed he has made the right decision after siding with Ballynagour.
Scudamore, who has not been in action since a heavy fall at Uttoxeter on March 19, will make his comeback at Aintree tomorrow when his rides include Betfred Bowl outsider Dynaste.
"I'm feeling great and can't wait to get back," he said.
Scudamore has chosen Ballynagour over two other David Pipe inmates in Soll and Vieux Lion Rouge.
He said: "It was a very tough decision as all three have a similar chance.
"Soll loves it round there, but is higher in the weights now, while Vieux Lion Rouge is an improving young horse.
"I went for Ballynagour as he has some very strong form with the likes of Cue Card and Silviniaco Conti and his run at Cheltenham suggested he is coming back to form."