Last year's winner Rock On Ruby is among a field of nine for the Stan James Champion Hurdle at Cheltenham on Tuesday.
Hurricane Fly and Binocular, the previous two winners of the two-mile blue riband, bid to regain their crown.
Harry Fry's Rock On Ruby will wear blinkers as he attempts to become the first horse since Hardy Eustace in 2004 and 2005 to retain his title.
Paul Nicholls, who officially trained Rock On Ruby last year, is represented by Zarkandar, who is unbeaten in three starts this season and the mount of Daryl Jacob with Ruby Walsh electing to ride Hurricane Fly.
As well as Binocular, the 2010 winner, Nicky Henderson saddles Grandouet and Khyber Kim.
The 2011 hero Hurricane Fly, trained by Willie Mullins, is the only Irish representative.
Countrywide Flame and Cinders And Ashes, winners of the Triumph and Supreme Novices' Hurdle respectively last year, take their chance while Balder Succes complete the line-up.
Cotton Mill was the sole withdrawal at the 48-hour final declaration stage. He is set to run on Friday in the Vincent O'Brien County Handicap Hurdle.