At $10 million, the Dubai World Cup was once again the world&rsquo;s richest race in 2010. Run at the new Meydan Racecourse for the first time, the World Cup received a $4 million purse increase this year, giving it some breathing room over the Melbourne Cup, which, thanks to a rise in purse money and the strength of the Australian dollar, jumped from $4.9 million in 2009 to $5.9 million and from sixth to second place.\r\nThe Japan Cup remained the world&rsquo;s third-richest race, at $5.6 million, an increase of about $160,000, thanks entirely to the continued strength of the yen against the U.S. dollar. The strong yen and purse increases to five classic trials run by the Japan Racing Association helped put 60 Japanese races on the list of the top 100 Thoroughbred flat races this year, up from 51. Aiding the Japanese push were increases to several races on the National Association of Racing&rsquo;s weekday calendar. The NAR had seven races in the top 100, including the JBC Classic, its first race to reach the $2 million mark.\r\nJapan asserted more than its usual dominance in the list of the top 100 Thoroughbred flat races this year as the strong yen and purse increases to five classic trials run by the Japan Racing Association helped to increase the number of Japanese races on the list from 51 to 60. Aiding the Japanese push were increases to a number of races on the National Association of Racing&rsquo;s (NAR) weekday calendar. The NAR now has seven races in the Top 100, including the JBC Classic, its first race to reach the $2 million mark.Prize money at the top level in Australia remains robust. Flemington&rsquo;s Golden Slipper Stakes, which was the world&rsquo;s richest 2-year-old contest and richest sprint, jumped from 18th to ninth place and was worth $700,000 more this year than it was in 2009.\r\n:: WORLD'S 100 RICHEST&nbsp;RACES\r\nThe richest race in America and the world&rsquo;s richest dirt race, the Breeders&rsquo; Cup Classic, held steady as the seventh most valuable race in the world despite a minor drop from $4,580,000 to $4,545,000. Largely because all of the Breeders&rsquo; Cup races were run on dirt this year at Churchill Downs, 15 dirt races were on the list, six in the U.S. and nine in Japan. Only three of the top 100 races &minus; the World Cup, the Dubai Golden Shaheen, and the UAE Derby &minus; were run on a synthetic track, whereas 84 were run on turf.\r\nThe top 100 list actually comprised 102 races because there was a three-way tie for 100th place.\r\nOnly three of the top 100, the World Cup, the Dubai Golden Shaheen and the UAE Derby, were run on a synthetic track, while 84 were run on turf, the total coming to 102 as there was a 3-way tie for 100th place.While Japan was way out in front with 60 races on the list, Hong Kong, where prize money is static, was second with 10, one fewer than it had in 2009 because the 1 1/2-mile Champion &amp; Chaters Cup slipped down to 103rd place at $1,027,200. The U.S. had nine on the list, two fewer than in 2009. The Haskell Invitational, increased to $1.25 million last year to attract the attention of Rachel Alexandra, was cut to $1.01 million this year and fell from 79th to 104th place. The Preakness, the 92nd richest race last year at $1.1 million, was worth $1 million this year and shared the 105th spot with eight other races: the Arkansas Derby, the Arlington Million, the Belmont Stakes, the Delta Downs Jackpot, the Pacific Classic, the Travers Stakes, the Godolphin Mile, and the Al Quoz Sprint, which had been worth $200,000 before being added to the Dubai World Cup card this year.\r\nEurope showed a marked decline, with only seven races in the top 100 this year, down from 13 last year. Big purse cuts in Ireland saw the Irish Champion Stakes fall from $1,426,200 and 61st place to an also-ran position at $967,000. The Prix de Diane (French Oaks) at $967,500 also slipped out of the top 100, but that was due entirely to the vagaries of the currency exchange market. Four restricted races &minus; the Goffs Million, the Goffs Fillies Million, the Tattersalls Million, and the Tattersalls Fillies 800 &minus; either had drastic purse cuts or were eliminated altogether.\r\nBy continent, Asia led the list with 76 races, North America 10, Oceania nine, and Europe seven. There were no changes in the order of the world&rsquo;s richest jump races. They are led by the Nakayama Daishogai at $1,816,604; the Nakayama Grand Jump at $1,546,838; Aintree&rsquo;s Grand National Steeplechase at $1,422,473; and Auteuil&rsquo;s Grand Steeple-Chase de Paris at $1,013,684.