Elusive Pimpernel had the highest rating of 144 by Timeform.

@ Prabhu

Yes 126 is the ceiling unless a horse beats Time and Tide at level weight 

If we observe the top rating of a class at RWITC it is 26 for Lowest Class going to 46 for 20-46 and so on

Difference of 26 comes from minimum stipulated class weight of 49kg and highest weight in a class which is 13 kg or 26 Rating points 

Highest Handicap race is 80-106 at RWITC while Kolkata has high Handicap race with starts at 95 

Howver for ceiling on Rating one can say the class is 100 and here the top Rating is 100+26 and that is how 126 is put as ceiling effectively it means in 80+ class it runs at 72kg 

Hope is clear 

@GODZILLA

Time and Tide is a champion sprinter. 

Oasis Star and ruffina also legend sprinter. 

The handicapped kept Time & Tide at the same rating 126 because, the horse did not give any new information to him.It has more to do with the quality of the opposition. May be on a day when a horse rated comparatively level challenges Time & Tide ,the handicapper may increase the rating.

Coming to the point raised by @ Precisely....may be a sprinter will not be able win over Derby distance ,but there is no reason why a quality stayed will not be able to win over a sprint.

  In 1989/90, Exhilaration won Indian Derby as well as Invitation Cup in Mumbai.He made his reappearance in a 1000 meter Race in Pune.In a field which had quality sprinters he was installed as a favourite (90/100 )..The tipsters were unanimous in their opinion that "the horse should complete the formalities".The Hindu remembered the old jargon " A quality stayed, after a long layoff should win over ANY distance "

The very next season ,I was witness to Star Contender winning a Class 1 sprint ,2000 guineas ,Derby ,and St.Leger in the Bangalore Winter.

@ Godzilla, Ratings have to be understood in their proper context.A 126 rated horse will not be able to beat a zero rated horse in a handicap race( If the zero rated horse carries 50 kgs ,126 rated horse will have to carry 88 kgs --- an impossibility !

Comment made by Godzilla is beyond my understanding. Every champion horse has its own distance. The best sprinter I have ever seen is Oasis Star. I won't expect her to win 2400. Nor would I expect Mystical and Elusive Pimpernel to win sprints. So this co relation of rating and distance sounds non sense

The Top most rating I have seen of a horse is 140 in India. There was not one but 6/7 of them who had 5/6 group 1 races on their name. 

Whats the point in Rating ? Can Time and Tide win a 2400 mtrs Race  despite high rating?