The nine-year-old fell three fences from home when still travelling well on his first attempt in 2013, while he looked a likely winner jumping the final obstacle in front last year before wandering across the track and eventually finishing fourth.
He arrives as favourite for the race this time after a fine campaign that has seen him win two of his three starts, including a second King George VI Chase on his most recent outing.
Silviniaco Conti galloped his rivals into submission that day, which Nicholls believes is indicative of his charge’s renewed zest.
“He made the running and galloped on really strongly,” said the Ditcheat handler.
“Something he was not doing last year was finishing his races.
“We found out after he won at Aintree last year he was suffering badly with gastric ulcers and we are on top of that now. The cheekpieces have also got him jumping sharper.
“Hopefully this year he is much better and on form he is the one they have to beat and he deserves to be favourite.
“You have to stay to win a King George. Look at See More Business, he won a Gold Cup and Kauto was the same.
“I’ve got no doubt about him staying whatsoever.”
Nicholls also fields Sam Winner, who beat Tuesday’s Festival winner The Druids Nephew at Cheltenham earlier in the season and was last seen finishing third in the Lexus Chase behind the reopposing Road To Riches.
The trainer said: “If you look at his form around Cheltenham he is not totally without a chance of finishing in the frame and he is a lively outsider.”
Bobs Worth is another former winner who is seeking a renaissance after finishing only fifth in his defence last year and eighth in the Lexus on his only start this term.
Trainer Nicky Henderson said: “Bob has been there for three Festivals – that’s a tough thing to do. Of course he has had tough races.
“For what he lacks in talent he puts together with his heart and soul.
“He hasn’t got the class of Sprinter Sacre and Simonsig, if you like, but he tries and he has to dig deep and that takes a lot out of them.”
Connections of Coneygree made the bold call to bypass the RSA Chase in favour of a crack at the main prize following his bloodless Feltham Chase success and his subsequent triumph in full company in the Denman Chase at Newbury.
Captain Christy was the last novice to win the race back in 1974 but Sara Bradstock, wife of trainer Mark, has shrugged off any concerns about that statistic.
She said: “The horse doesn’t know what the race is.
“He doesn’t know if it’s the Gold Cup or the RSA, so I think the statistics are meaningless.
“He’s a front-runner and will run his race. The only question, and what we have to find out some time, is whether, when push comes to shove, he’s good enough at this level.
“Obviously we would love some rain before the race.
“He’s been working well at home on good ground and I’m sure good ground wouldn’t be a problem, it’s what it would mean for the other horses.
“He’s a very talented, but fragile, horse so while we have him fit and well, this seemed to good an opportunity to miss.”
The Giant Bolster is at the other end of the scale as he has his fourth start in the race, having finished second, fourth and third for David Bridgwater.
He said: “It’s an open race and hopefully he’ll run as well as he has done the last three years.
“I hope they go very quick. That will suit us. I don’t think they will mess around.
“As long as we get competitive again I’ll be thrilled. He’s as good as he was last year, no doubt.”
Smad Place takes his chance, but Alan King is not sure the trip will suit, despite finishing second in the BetBright Cup over just shy of the Gold Cup trip.
He said: “I think he has come forward, but whether he wants three-and-a-quarter miles I’m not sure as I am not convinced he is an out-and-out stayer.”