Arrogate appeared well on his way to making a successful title defense in the $6 million Breeders’ Cup Classic when opening 2017 with smashing wins in the Pegasus Cup Invitational (G1) and Dubai World Cup (G1), but the landscape changed dramatically following a pair of setbacks at Del Mar this summer.

His vulnerability resulted in Gun Runner being installed as 9-5 morning line Classic favorite and the Steve Asmussen-trained colt will certainly take some beating following a trio of outstanding wins in the Stephen Foster (G1), Whitney (G1) and Woodward (G1), scoring by a combined 22 ¼ lengths. The 4-year-old son of Candy Ride is winless from three previous attempts at 1 ¼ miles, but Gun Runner appears much stronger presently and must be viewed as a serious threat to overwhelm the competition with his talents.

After going off form with a dismal fourth as the 1-20 favorite in the July 22 San Diego (G2), Arrogate returned four weeks later with an improved second in the Pacific Classic (G1). Bob Baffert and Mike Smith are confident the 4-year-old Unbridled’s Song colt is rounding back into top shape based upon morning exercises but the stalker was done no favors when receiving Post 1 at Monday’s draw. Arrogate is listed as the early 2-1 second choice.

If Arrogate does come up short, Baffert still has a chance to derail Gun Runner with three other quality Classic entrants: Pacific Classic victor Collected, Travers (G1) and Pennsylvania Derby (G1) hero West Coast and Awesome Again (G1) winner Mubtaahij.

Click here to see the 2017 Breeders’ Cup fields with morning-line odds and connections

The $4 million Breeders’ Cup Turf (G1) precedes the Classic and Ulysses and Highland Reel highlight deep six-horse international contingent. European-based runners have captured the seven of the last nine editions of the 1 ½-mile race.

Fourth in last year’s Turf as a 3-year-old, Ulysses appears much-improved at age 4 for four-time Turf winner Sir Michael Stoute, recording Group 1 wins in the Juddmonte International and Eclipse in recent months, and the son of Galileo exits a third to superstar Enable in the Prix de l’Arc de Triomphe (G1). Highland Reel will make a title defense for Aidan O’Brien, who leads all conditioners with six Turf wins, and disregard any bad performance overseas on soft ground; the classy 5-year-old prefers firmer conditions. He’ll be forwardly-placed from the start with Ryan Moore.

Other Turf runners of interest include Beach Patrol, the leading American-based entrant following wins in the Arlington Million (G1) and Joe Hirsch Turf Classic (G1); and Grade 1 winners Oscar Performance and Sadler’s Joy.

Horseplayers will have options in a contentious 14-horse edition of the $2 million Mile (G1). Four-time Group 1 winner Ribchester heads a strong international cast that includes notables Roly Poly and Lancaster Bomber, and World Approval is a candidate to hold his own against all challengers after discovering his forte at eight furlongs for Mark Casse, recording excellent triumphs in the Fourstardave (G1) and Woodbine Mile (G1) in the last two appearances.

Bolt d’Oro will put his unbeaten record on the line against 11 rivals in the $2 million Breeders’ Cup Juvenile (G1) and it will be no surprise to see him bet down significantly from his 9-5 morning line price following a tour-de-force performance in the FrontRunner (G1) at Santa Anita.

The $2 million Juvenile Fillies (G1) has a much more wide-open feel than its male counterpart, with leading contenders including last-out prep winners Heavenly Love, Moonshine Memories and Separationofpwers.

Drefong is back for a title defense against nine foes in the $1.5 million TwinSpires Breeders’ Cup Sprint (G1), with Santa Anita Sprint Championship (G1) victor Roy H and Mid-Atlantic star Imperial Hint among his main opponents.

Unique Bella is an imposing presence in the $1 million Filly & Mare Sprint (G1). Listed as 9-5 favorite among 14 runners, the gray daughter of leading sire Tapit was redirected to one-turn events after being sidelined for seven months earlier this year and the talented sophomore miss is expected to point toward the Breeders’ Cup Distaff (G1) next season. She will square off against a cast of elders including Finley’sluckycharm, Paulassilverlining and Skye Diamonds.

Lady Eli will be one of the day’s strongest favorites when she makes her career finale in the $2 million Filly & Mare Turf (G1). A nose second in the 2016 edition, the Chad Brown-trained mare figures to appreciate the cut back to a 1 1/8-mile distance at Del Mar and is an overwhelming 5-2 choice on the morning line among 14 runners. Multiple Group 1 scorer Rhododendron probably has the best chance at an upset for Coolmore/O’Brien and Queen’s Trust is back for a title defense but has dropped all five starts this year.

Lady Aurelia showed her class overseas this year, recording a convincing tally in the King’s Stand (G1) at Royal Ascot and a nose second in the Nunthorpe (G1) at York, and the front-running sophomore filly is the one to beat in the $1 million Turf Sprint (G1). Her foes include Nunthorpe winner Marsha and Disco Partner, who established a new world record winning the Jaipur (G3) at Belmont Park in June.