1 Tidal Bay
Trainer: Paul Nicholls 14/1
Top weight, but theoretically offered a chance of winning by the handicapper, this high-class chaser remains in tremendous form despite advancing years. Quirky hold-up style should ensure he appears towards the end, and stays well. Rating: 8 out of 10

2 Long Run
Nicky Henderson14/1
Gold Cup and dual King George winner would be becoming the first to ever collect all three prizes if scoring at Aintree, but must be a big question mark of him completing as he is error-prone. Clear contender, but risky proposition. Rating: 6

3 Hunt Ball
Nicky Henderson66/1
Former progressive handicapper has run well on both starts since returning from a disastrous spell in America but must be a big doubt he will stay. Rating: 3

4 Triolo D'alene
Nicky Henderson20/1
Already successful over the big green fences in last year's Topham, he maintained his progress by landing November's Hennessy and likely to have needed comeback run in the Gold Cup. Plenty of weight, but given plenty of respect. Rating: 8

5 Rocky Creek
Paul Nicholls20/1
Has run solidly in both the Hennessy and Argento and takes in the National after Gold Cup bid was thwarted by a bout of ringworm. Might just be a little inexperienced this time around. Rating: 6

6 Quito De La Roque
Colm Murphy 50/1
Would once have made great appeal on old form as a safe-jumping stayer with a touch of class, but unless he is hiding his light under a bushel, has not inspired much confidence this season. Rating: 4

7 Colbert Station
Ted Walsh 25/1
Worse off at the weights than when unseating Tony McCoy at The Chair 12 months ago and has had two more mishaps since then. Not one to rely upon, despite canny connections. Rating: 3

8 Walkon
Alan King 50/1
One note of encouragement was his second place in last year's Topham but looks very unlikely to see out the distance. Rating: 3

9 Balthazar King
Philip Hobbs 25/1
Outstanding cross-country performer gave his supporters a run for their money by leading for more than a circuit last year but hard to see him doing any better this time. Rating: 3

10 Wayward Prince
Hilary Parrott 50/1
Has essentially started to go backwards after making a reasonable start for his trainer and makes very little appeal. Rating: 1

11 Mr Moonshine
Sue Smith 33/1
Pulled-up last year behind but in far better form now and is a more mature type than his tearaway former self. Finished third in the Becher and a lively outsider without being an obvious winner. Rating: 6

12 Teaforthree
Rebecca Curtis 9/1
Gave connections the thrill of a lifetime when third last year and arrives in similar sort of shape but is short enough in the betting for what he is. Rating: 6

13 Across the Bay
Donald McCain 40/1
Slightly unlucky to finish no higher than 14th last year and has completed the course again since but a below-par most recent outing tempers confidence. Rating: 4

14 Double Seven
Martin Brassil 25/1
Prolific winner during the early part of the season — including two regional nationals in Ireland — he appears to have long been earmarked for the race by knowledgeable trainer. Should be better than reappearance, and looks interesting. Rating: 9

15 Battle Group
Johnny Farrelly 40/1
Managed a terrific feat of winning over both hurdles and fences at the 2013 meeting but has become increasingly cantankerous and is better left alone. Rating: 1

16 Buckers Bridge
Henry de Bromhead 66/1
On the plus side ran his best race to date when third in the Bobbyjo but is not short of negatives including inexperience and stamina doubts. Rating: 4

17 Lion Na Bearnai
Tom Gibney 33/1
Only won one uncompetitive chase since his 33-1 success in the 2012 Irish National, is out of form and becoming a bit long in the tooth. Rating: 1.

18 Prince De Beauchene
Willie Mullins 20/1
Has missed the last two renewals due to setbacks. Commands respect due to his connections and a big run would be no surprise, but suspicion remains his time has passed. Rating: 7

19 Monbeg Dude
Michael Scudamore 16/1
Gallant stayer, who has earned his position at the top of the market due to fine performances at Cheltenham and Chepstow. However, he is a notably erratic jumper, which is not a good thing around here. Rating: 5

20 Big Shu
Peter Maher 33/1
The each-way selection of some good judges would appear to have been trained as much with the National in mind as the retention of Cheltenham cross-country title, in which he was third. Might lack a little speed. Rating: 7

21 Burton Port
Jonjo O'Neill 20/1
Placed in 2012 Gold Cup and Betfair Bowl for Nicky Henderson and just started to emerge from a long spell in the wilderness for his new trainer. Looked a new horse when second at Newbury last month, and with the promise of more to come, is very well treated at the weights. Rating: 10

22 Our Father
David Pipe 50/1
Erratic, if sometimes capable, grey who has been very much more miss than hit of late. Head rules over heart, and must be discarded. Rating: 2

23 Mountainous
Richard Lee 40/1
Welsh National winner requires a mudbath to be seen at his best and must be a real danger things will happen too fast for him. Rating: 5

24 The Rainbow Hunter
Kim Bailey 33/1
Did not last long last time around, which is a concern, but looked a greatly improved horse this season in winning the Sky Bet Chase and ought to be in shortlists. Rating: 8

25 Vintage Star
Sue Smith 40/1
Trainer must not be underestimated but has done all his winning in small fields, and does not look good enough. Rating: 3

26 Chance Du Roy
Philip Hobbs 33/1
Goes well over the fences, finishing second in a Topham and landing the Becher last December. Only slight doubt is about the extra trip, but has a light weight and likes better ground, so must be kept on side. Rating: 9

27 Hawkes Point
Paul Nicholls 33/1
Stays well for leading stable but shown nearly all his form on soft ground and only ever won once over fences. Bypassed, admitted with a touch of reluctance. Rating: 3

28 Kruzhlinin
Donald McCain 66/1
Kelso specialist not used to this level of competition. Rating: 1

29 Pineau De Re 20/1
Dr Richard Newland Stayed well when trained in Ireland but taken another step forward in Britain, laughing at his rivals at Exeter in January then looking slightly unlucky to be only third in the Pertemps Final. Interesting horse who must be taken seriously. Rating: 8

30 Golan Way
Tim Vaughan 66/1
Likeable front-runner who could make a bold show on the first circuit without being there at the end. Rating: 2

31 Twirling Magnet
Jonjo O'Neill 66/1
Rather in-and-out chaser who is still a novice and has a habit of making the odd mistake. Looks the least likely candidate for his stable. Rating: 3

32 Vesper Bell
Willie Mullins 50/1
Stays well, as finished a narrow second in a marathon event at the Punchestown Festival and could be better than shown so far this season, but a fall in the Becher Chase dampens optimism. Rating: 4

33 The Package
David Pipe 33/1
Unseated in the race back in 2010, and the fragile gelding has only raced eight times since then. Caught the eye on comeback at Cheltenham and appears to have more than a tough of stable confidence. Rating: 8

34 Raz De Maree
Dessie Hughes 40/1
Foolish to completely ignore any runners from this stable but has shown very little form in more than a year. Rating: 4

35 Rose of the Moon
David O'Meara 50/1
New trainer coaxed the gelding back to form with a clear victory at Wetherby and has a nice weight but must cut out jumping errors if he is to be involved. Rating: 5

36 Shakalakaboomboom
Nicky Henderson 33/1
Ninth in 2012 but not exactly set the pulses racing in three comeback runs, even though he is being trained for this. Bit too much to take on trust. Rating: 4

37 Alvarado
Fergal O'Brien 33/1
Win at Cheltenham in November makes for good reading, but this tricky ride has not proved the most reliable during his career and is probably best left alone. Rating: 3

38 Last Time D'albain
Liam Cusack 50/1
Looked all over a future National contender when third in last year's Topham. Not exactly proved the omens correct in two hurdle outings and one chase, but lurks at the bottom of the weights and there are many worse long shots. Rating: 7

39 One In A Milan
Evan Williams 66/1
His fourth place finish in the Welsh Grand National earlier this season gives him some sort of chance and he has had two readying runs over hurdles since. His trainer has had horses run well in this in the past, so not a completely forlorn hope. Rating: 5

40 Swing Bill
David Pipe 66/1
Not getting any younger, but was sixth a year ago and continued his love affair with the track when fifth in the Becher Chase earlier this season. Looks a solid bet to get round, but surely won't be winning. Rating: 3