Sea The Stars has been given the highest rating since Peintre Celebre over a decade ago in the publication of the World Thoroughbred Rankings.
John Oxx's exceptional colt, winner of six Group Ones, including the Derby and the Prix de l'Arc de Triomphe, was rated 136 by the panel of handicappers and racing secretaries affiliated to the International Federation of Horseracing Authorities.
The previous best assessment went to French ace Peintre Celebre, on 137, under former international classifications back in 1997.
The handicappers felt Sea The Star's finest performance of the season came in the Tattersalls Millions Irish Champion Stakes last September.
Second best in the rankings was Freddie Head's dual Breeders' Cup Mile-winning filly Goldikova on 130, rated the best filly miler since Miesque, who replicated her American achievements in the 1980s.
She was ahead of Aidan O'Brien's Rip Van Winkle (129) and Fame And Glory (128).
The two great American fillies Zenyatta (128) and Rachel Alexandra (127) filled the next places in the table.
The former became the first female ever to win the Breeders' Cup Classic and is the highest-rated filly or mare on a non-turf surface since Inside Information (129) back in 1995.
Rachel Alexandra, who has also captured the hearts of her nation, was reckoned by the handicappers to have produced her best performance in the Haskell Stakes in August.
The top sprinters in the world were Australian-trained King's Stand winner Scenic Blast and the Hong King speedball Sacred Kingdom, both on 122.
They were given the same rating as legendary stayer Yeats, who captured a fourth Ascot Gold Cup in June.
O'Brien's St Nicholas Abbey emerged at the top of the two-year-old ratings following his win in Doncaster's Racing Post Trophy.
In earning a figure of 124, he became the first Racing Post Trophy winner to head the list since Celtic Swing in 1994 - well clear of recent winners such as Authorized, Motivator and High Chapparal.
Criquette Head-Maarek was responsible for the top filly for the fourth time in her training career with Special Duty (117).