I'm not the worlds best at ratings and to what that equates to in terms of lengths. So if the king George was run tomorrow with both horses running to there highest rating what distance would Arkle beat Kauto?
Timeform jumps handicapper Phil Turner gave Kauto 191 at his peak, the highest figure since Timeform’s Chasers & Hurdlers series began in 1975/76. Turner also commented “we're still confident Arkle was the greatest horse in National Hunt history, the fact we rate Kauto Star as the best since his era should be viewed as a huge compliment when one considers some of the names who'd previously vied for that title”.
Randall and Morris, calculating an equivalent rating for Arkle, reckon he was 212.
It's virtually impossible to quantify how far Arkle would have beaten Kauto.
This is not to say that Kauto is overall number 2 though. Horses like Easter Hero, Flyingbolt, Golden Miller, Dunkirk, Mill House, Captain Christy, should be considered and in more recent times Burrough Hill Lad, Desert Orchid, Denman, Moscow Flyer and others put up big performances.
Dunkirk was a favourite of mine. In 1965 he beat Mill House (at levels) by 15 lengths at Ascot and defied 12st 7lb in the Mackeson giving 31lb to the runner up. He broke his neck when trying to match strides with Arkle in the 1965 KG.