Happily will put trainer Aidan O’Brien in the familiar role of starting the favorite in Sunday’s Group 1 Irish 1000 Guineas at The Curragh.The legendary trainer has won the one-mile turf race for 3-year-old fillies a record-equaling seven times, but has a mixed record with favorites of late. Winter won last year for O’Brien at odds of 8-13, but Found (5-4) and Minding (4-11) could only finish second as favorites in 2015 and 2016.As of Friday, Happily was 3-2 in the future book to win the $465,200 Irish 1000 Guineas, which drew a field of 13, including four trained by O’Brien. Owned by the Coolmore partnership of Susan Magnier, Michael Tabor, and Derrick Smith, Happily was third as the 5-2 favorite in the English 1000 Guineas on May 6 at Newmarket in her only start this year.Last year, Happily won consecutive Group 1 races in Ireland and France before finishing last of 14 in the Breeders’ Cup Juvenile Fillies Turf at Del Mar in November.Clemmie, trained by O’Brien, and Soliloquy, owned by Sheikh Mohammed’s Godolphin Racing, seem best suited to beat Happily.Clemmie, a 5-1 chance as of Friday, has not raced this year. In 2017, she won 3 of 5 starts, ending the campaign with three consecutive graded stakes wins. In her only start in a Grade 1, Clemmie won the Cheveley Park Stakes at six furlongs on turf at Newmarket. The Irish 1000 Guineas will be Clemmie’s first start at a mile.Soliloquy, trained by Charlie Appleby, won the Group 3 Nell Gwyn Stakes at seven furlongs April 18 at Newmarket, but was ninth behind Billesden Brook in the English 1000 Guineas, losing by 3 1/4 lengths. Soliloquy was a 9-2 chance for the Irish 1000 Guineas as of Friday.O’Brien has an excellent chance to sweep the two Group 1 races at The Curragh on Sunday if Cliffs of Moher performs to expectations against four rivals in the $348,900 Tattersalls Gold Cup at 1 5/16 miles on turf for older horses.Cliffs of Moher, second in the 2017 English Derby, won the Group 2 Mooresbridge Stakes on May 7 at Naas Racecourse in Ireland. The Tattersalls Gold Cup will be class test for the English shipper Defoe, who has won six of his last seven starts, including the Group 2 Jockey Club Stakes on May 5 at Newmarket. The only loss in that span was a 10th in the Group 1 English St. Leger last September.