Harbinger, the highest rated four-year-old since Alleged in 1978, was officially 6lbs better than any other horse in the world last year and 7lbs better than Epsom Derby and Arc winner Workforce.
But the handicappers could not separate Dream Ahead and Frankel at the top of the two-year-old rankings.
Announcing the 2010 World Thoroughbred Rankings yesterday, senior BHA handicapper Phil Smith explained that Harbinger's rating of 135, 1lb lower than Sea The Stars the previous year, was conservative and there had been an argument to rate him 137 on his 11-length King George victory at Ascot.
"We went through the runner-up Cape Blanco and it's very rare to use a horse beaten so far as a marker," he said. "What characterised Harbinger's season was the form of all his wins worked out."
Workforce (128), which shared the leading three-year-old honours with 2,000 Guineas winner Makfi, proved that the "much-maligned great race, the Derby, was alive and kicking". The last four winners of the race have ended the season as top three-year-old.
Matthew Tester, the two-year-old handicapper, had Dream Ahead (126) and Frankel (126) 6lbs better than their nearest rivals.
However, Tester felt the potential to go further was with Frankel. "I felt Dream Ahead was physically ahead of the average. If he had a more fashionable trainer and more fashionable sire they'd be talking about the next Sea The Stars."
"But I think 2011 is all about Frankel and whether he reaches his full potential."
The handicappers' views of horses for the following season are always interesting. Last year Tester went for Workforce, Canford Cliffs and St Nicholas Abbey. This time he nominated Zoowra and Carlton House while Irish handicapper Gary O'Gorman picked out Kissable, Alanza and Handassa. (© Daily Telegraph, London)