Based on the provided ratings and additional comments, here is a report on the contenders:

1. Big Rock – With a total rating of 128, Big Rock stands out as the 2nd highest-rated horse in the field. He has shown remarkable improvement since moving to his current yard, winning impressively in handicap and Listed events. Big Rock’s recent win in the Prix de Guiche by making all is particularly noteworthy, indicating his ability to handle the distance and course conditions. With his consistent form and a favorable ground, Big Rock is a strong contender and should not be underestimated.
2. Marhaba Ya Sanafi – has a total rating of 131, making him the highest-rated horse in the field. His surprise victory in the Poulains at Longchamp, where he defeated American Flag, showcases his potential to compete at a high level. With enough stamina on his dam’s side, Marhaba Ya Sanafi is expected to handle the longer trip. His exceptional rating and recent success make him a top contender for this race.
3. American Flag – Despite being a beaten favorite in the Poulains, American Flag has a solid total rating of 125. He previously defeated Marhaba Ya Sanafi in a Longchamp Group 3 race, emphasizing his ability to perform well against strong competition. However, there are some concerns about his stamina for the longer trip. While he may face a challenge, American Flag has the talent and potential to make an impact in this race.
4. Continuous – With a total rating of 122, Continuous has displayed promising form in previous races. He won a Curragh maiden and followed it up with a Group 3 victory at Saint-Cloud. His third-place finish in the Dante, amongst race-fit rivals, suggests he is capable of performing well against tough competition. Having proven himself over similar distances, Continuous should be considered a serious contender.
5. Epictetus – Epictetus has a total rating of 122, having placed behind Auguste Rodin in the Group 1 Vertem Futurity at two. While he had a less impressive performance in the Dante, finishing fifth, the addition of cheekpieces may help him regain focus. A bounce-back performance from Epictetus cannot be ruled out, but he will need to demonstrate significant improvement to contend with the top-rated horses.

Conclusion:

Based on the report, the top contenders for the upcoming race are Big Rock and Marhaba Ya Sanafi. Big Rock has displayed consistent improvement and dominant performances, making him a formidable competitor. However, Marhaba Ya Sanafi’s exceptional rating and recent success in the Poulains suggest that he has a strong chance of winning the race. American Flag and Continuous also possess the ability to challenge for victory, but they will need to overcome certain considerations. Epictetus, while not among the highest-rated horses, shouldn’t be entirely dismissed as he has previously shown promise. The outcome of the race will depend on the performance and conditions on the day, but Big Rock and Marhaba Ya Sanafi appear to have exceptional chances based on the information provided.