This year's official start numbers for the RST Superbike and PokerStars Senior races at the Isle of Man TT have caused a surprise with a number of major changes compared to recent seasons.

Kiwi Bruce Anstey will set off at number two on Clive Padgett's Honda in a change from his traditional number five, which he has used every year since 2004 with the exception of 2010 (No.1).

Outright lap record holder John McGuiness retains the number one plate and leads the field away on the official Honda Racing Superbike, while James Hillier moves to number three on the Quattro Plant Muc-Off Kawasaki.

Bingley Bullet Ian Hutchinson climbs the order to number four on the Tyco BMW, the same number he used in 2010 when he became the only rider ever to win all five major solo races at the TT.

Ten seconds behind Hutchy is another of last year's revelations and a potential race winner in the shape of Peter Hickman. The eighth fastest rider of all time will line up on the JG Speedfit Kawasaki and has the ideal target in front of him in Hutchinson although he could well be occupied with the rider starting behind him - Michael Dunlop.

After a problematical 2015 TT campaign, Dunlop on the Buildbase Hawk Racing BMW is back at the start number that saw him claim a hat-trick of 1000cc wins in both 2013 and 2014 and he will be hoping that it proves to be a lucky six.

Previous two-time Supersport TT winner Gary Johnson will again have the number seven plate, this time on the Penz13.com BMW, and will be followed down Glencrutchery Road by William Dunlop on the CD Racing Yamaha R1 and the evergreen Michael Rutter (Bathams/SMT Racing BMW). As in previous years, Manxman Conor Cummins completes the top ten on the second Honda Racing machine.

There's exciting news at number 11 with Aussie Cameron Donald moving back up the grid from last year's start place of 19. Donald finished second in the Superbike race for three successive years between 2011-2013 and the Adelaide-based rider will again look to be back up at the front of the field on his return to Ulster team Wilson Craig Racing.

Silicone Engineering is a new team among the seeded outfits in the number 12 spot but it's familiar territory for rider Dean Harrison, who starts one position ahead of Northern Ireland's Lee Johnston on the East Coast Construction BMW.

Manxman Dan Kneen on the Mar-Train Racing Yamaha starts ten seconds later with Australian ace David Johnson completing the top 15 on the factory Norton. Going off at 16 will be Ryan Farquhar, who rides the second Tyco BMW.

Dan Stewart (Wilcock Consulting Honda), Martin Jessopp (Riders Motorcycles BMW), Steve Mercer (Jackson Racing Honda) and last year's Bennetts Lightweight TT winner Ivan Lintin, who's amongst the Superbike seeds for the first time on the Devitt RC Express Racing Kawasaki, complete the top 20.

There's no shortage of talent outside the top 20 with the likes of Alan Bonner, Dan Cooper, Sam West, Daniel Hegarty and Ryan Kneen all back for another effort as is the veteran Ian Lougher on the intriguing Suter 580cc two-stroke.

With the top 20 seeded riders all having lapped comfortably over 127mph, it's the fastest top end field ever assembled.

Eight newcomers will get their first race action around the Mountain Course in the 1000cc races - Italian Alessandro Polita, British Supersport rider Ben Wilson, British Superstock regulars Victor Cox and Michael Booth, Irish Championship frontrunner Seamus Elliott, Jochem van den Hoek (Holland), Andre Pires (Portugal), and Cornwall's Forest Dunn.