Cheltenham World Hurdle:Bookmakers do not believe he can be turned over, but trainer Paul Nicholls and owner Andy Stewart have sounded a note of caution over the chance of Big Buck's landing a second victory in the Ladbrokes World Hurdle at Cheltenham on Thursday.
The quirky but ultra-talented seven-year-old is unbeaten in six starts over timber since unseating Sam Thomas in the 2008 Hennessy Gold Cup.
He is long odds-on to repeat his Festival success with last year's runner-up Punchestowns now competing over fences, but connections feel his "quirky" nature will one day catch him out.
Nicholls said: "He is a real old character at home and I am sure he will get himself beat one day by pulling himself up.
"The better the race, the better he is and I can't say that he is a banker due to his character.
"I have a feeling Tidal Bay will run well but on form we will win - but one day he will get himself beat."
Stewart added: "He sets the standard on form and I think Tidal Bay and Karabak have a lot to find.
"He is ever so well but 4-7 is a stupid price as he could step on a stone or something.
"I couldn't be happier with him but he will get himself beat one day as he is a quirky sort."
Punchestowns' trainer Nicky Henderson will this time be represented by Sentry Duty who has his stamina to prove tackling three miles for the first time.
The eight-year-old successfully stepped up to two and a half miles at the track on New Year's Day but Henderson freely admits they are heading into the unknown.
He said: "The race might be short of pace as Sentry Duty won't be making it like Punchestowns did, which in a way set things up for Big Buck's.
"Big Buck's has done everything and I respect him. Tidal Bay is interesting as I was never happy watching him jump fences but he is a real contender back over hurdles.
"Sentry Duty will be there at two and a half miles and maybe at two and three-quarters but after that, we will be into unknown territory.
"He needs to be very, very fresh and I had no intention of finding out if he stays before the race."
Howard Johnson certainly knows what it takes to win the World Hurdle having saddled Cheltenham legend Inglis Drever to a hat-trick of successes.
This year he is represented by 2008 Arkle Trophy hero Tidal Bay, but the Durham handler admits he does not measure up to his former stable companion.
"I had been thinking about putting Tidal Bay back over hurdles because he wasn't having a cut at his jumps. He was just backing off a bit," said Johnson.
"I was pleased with the way he won the Cleeve Hurdle, he has a good record round Cheltenham.
"He's in good order and as long as the ground is good, he'll be fine.
"He's good but he's no Inglis Drever, you only get one like him and it was some achievement to win three World Hurdles.
"It would be good to win another one with Tidal Bay but as long as he comes back safe and well, that's the main thing."
Mouse Morris' 2006 Cheltenham Gold Cup hero War Of Attrition returns to the scene of his finest hour and while he may not be the force of old, two successive victories over timber suggest he should not be dismissed.
"I couldn't be happier with him and he seems to have travelled over well, he seems to know he's back at Cheltenham," said Morris.
"He's getting on now and isn't as quick as he was so hopefully the ground isn't too quick, but we'll see what happens.
"He seems in great form and this is his last season before he retires, so we'll give it a go.
"If he could run into a place I'd be over the moon with him."
His big-race jockey Davy Russell is even more confident of a bold showing in ground conditions which he believes will suit.
"He is over-priced and people have lost a bit of respect for him," said Russell.
"He is a dangerous man here having won over all distances, over hurdles and fences. (He) is back to somewhere near his old self and I think he has a great chance.
"He is better on better ground and on a bigger day and he will hopefully show improved form in the conditions."
Willie Mullins' Cousin Vinny makes his third visit to the Festival having won the Champion Bumper in 2008 and finished fifth when sent off favourite for the Supreme Novices' Hurdle 12 months ago.
The seven-year-old is back over the smaller obstacles having failed to rediscover his best form over fences, and Mullins feels he has decent claims of making his presence felt.
"We haven't seen the best of him this season as he was just jumping too careful over fences, so he hasn't got the good runs under his belt," said Mullins.
"However, his last few bits of work at home would suggest he's coming back to himself and he has travelled much better and settled in better than he had last year.
"It's coming together for him and while he has a big task, he has form to suggest he has a chance."