SEA THE Stars has been officially rated the best racehorse in the last dozen years, but his trainer, John Oxx, believes the great Guineas-Derby-Arc winning hero never even came close to revealing the full extent of his ability.

After a vintage 2009 for Irish trained horses, and “a year of exceptional racehorses” generally, the top three colts to race in 2009 were based in Ireland with Rip Van Winkle (129) and the Irish Derby-winner Fame And Glory (128) boasting ratings from the International Federation of Horseracing Authorities that would normally place them top of the pile.

However, both of Aidan O’Brien’s stars were eclipsed in a historic campaign by Sea The Stars whose unprecedented six-from-six Group One season has earned him a mark of 136 in the World Thoroughbred Rankings announced yesterday.

That 136 is the highest mark achieved since the Arc winner, Peintre Celebre, earned 137 in 1997 and it is also the highest rating awarded to an Irish horse for quarter of a century since El Gran Senor’s 138 in 1984.

Oxx, however, believes Sea The Stars’ style of racing meant that handicappers never got to judge the full range of his talent.

“He was never going to get a rating that reflected his ability. You know that when you have Mick Kinane telling you that the horse only showed 75 per cent of what he could do in any race. I prefer to judge him by his unique achievements and the manner and style of his wins,” the Curragh trainer said yesterday.

“It’s still a very impressive rating, one of the best ever, but handicappers are notoriously conservative. We saw that the year before when Zarkava wasn’t even put on 130 or better. So I was never really bothered about his rating,” Oxx added.

Ireland’s senior handicapper Garry O’Gorman acknowledged the difficulty of rating Sea The Stars but said that is a result of horses with his racing style.

“Horses like Zarkava and Zenyatta are the same, horses that do what they have to do without being extravagant,” he said.

“God knows what they would have achieved if there had been other horses around to drag it out of them.”

Nevertheless, since the World Thoroughbred Rankings started in their current format in 2004, Sea The Stars has altered the landscape with his 136 easily the best mark achieved in that time, a full 5lb clear of Manduro.

Next best in yesterday’s list is the super French filly Goldikova (130) who is on course to attempt an unprecedented Breeders’ Cup Mile hat-trick at the end of the year.

She is rated 2lb better than the American superstar Zenyatta, winner of the Breeders’ Cup Classic, who in turn is judged to be marginally superior to America’s other top filly, Rachel Alexandra.

A remarkably successful year for Irish-based horses was completed in the much-prized juvenile ranks with the unbeaten St Nicholas Abbey the fifth Irish two-year-old in a row to top the European rankings.

Aidan O’Brien’s Racing Post Trophy winner is on a mark of 124, equal to George Washington’s mark, but behind New Approach in 2006 who achieved a rating of 126. Ireland’s champion trainer also has the third highest-rated two-year-old in Europe in Jan Vermeer (119), who was an impressive winner of the Criterium International at Saint-Cloud in October while O’Brien’s Dewhurst winner, Beethoven, is one of several on a mark of 117.

“You would be loath to mention anything in the same breath as Sea The Stars but it can happen that great horses come along together. Mill Reef and Brigadier Gerard were in the same year. Nijinsky the year before,” Garry O’Gorman said.

“Montjeu has sired three Group One-winning two-year-olds, Motivator, Authorized and Fame And Glory. St Nicholas Abbey has achieved much more than them at two and judged on the others, you could expect St Nicholas Abbey to improve by 10lb next season,” he added.

“All things being equal, you would have to be very hopeful for him and indeed Jan Vermeer.”

Yeats, the four-time Ascot Gold Cup winner, is again rated the world’s top stayer.

Top-rated horses of 2009

136

Sea The Stars (JM Oxx) (Ire)

130

Goldikova (F Head) (Fra)

129

Rip Van Winkle (A P O’Brien) (Ire)

128

Fame And Glory (A P O’Brien) (Ire)

Zenyatta (J Sherieff) (US)

127

Rachel Alexandra

(S Asmussen) (US)

126

Cavalryman (A Fabre) (Fra)

Conduit (M Stoute) (Brit)

Gio Ponti (N Clement) (US)

Gladiatorus (Godolphin)(UAE)

Youmzain (M Channon) (Brit)

Top two-year-olds of 2009

124

St Nicholas Abbey (A P O’Brien) (Ire)

120

Passion For Gold (Godolphin) (UAE)

119

Jan Vermeer (A P O’Brien) (Ire)

118

Arcano (B Meehan) (Brit)

Canford Cliffs (R Hannon) (Brit)

Siyouni (A de Royer-Dupre) (Fra)

Vale Of York (Godolphin) (UAE)

117

Awzaan (M Johnston) (Brit)

Beethoven (A P O’Brien) (Ire)

Pounced (J Gosden) (Brit)

Special Duty (C Head-Marek) (Fra)