ACES was an annual flying competition hosted by the Black Baron and held in Kinderdijk, Holland. The objective was for teams to dogfight against each other in an arena using airplanes, typically of the bi-winged and tri-winged variety. Each pilot would get eliminated until there was one pilot standing, and that pilot would score the victory for their team. The winning team would then move onto the semifinals, and the winner of that round would go up against the reigning champion, Team Black Baron, in the finals.
The ACES competition was created by Penelope, under the guise of the Black Baron, in the hopes of attracting worthy opponents. Participants included teams from various countries, as well as teams led by Muggshot and Penelope herself. Penelope went on to become the undefeated champion of the competition, partly because she would have her gunships shoot down anyone who was about to win.
To ensure fair competition among the other participants, Penelope forbade any competitors to leave the hotel after sunset. She also kept the flight roster a secret to keep teams from finding out who their opponents were until the day of a dogfight. Despite these rules, teams were often the victims of "late-night hi-jinks." They would have their airplanes, or themselves, sabotaged the night before a dogfight. After meeting Bentley online, Penelope offered to join the Cooper Gang if they could defeat the Black Baron in the upcoming ACES competition. During the competition, Penelope helped Bentley protect Team Cooper's biplane from Muggshot. Meanwhile, Team Cooper framed Team Belgium and Team Iceland for sabotaging each other, that way Sly Cooper could stand a chance in the semifinals and move on to the finals.
The final round was a three-way battle between Team Cooper, Team Black Baron and Team Muggshot. However, Team Muggshot was crippled after their leader was arrested by Carmelita Fox. During the dogfight, Sly nearly destroyed Penelope's airplane. Resorting to her tricks, she called in her gunships, but thanks to Bentley, they were destroyed before they could sabotage Sly's plane. Both pilots abandoned their planes and battled on the wing of a passenger jet. Sly bested Penelope and exposed her identity as the Black Baron. Before explaining herself, Penelope crowned Team Cooper as the champions of the ACES competition. With her subsequently joining the Cooper Gang and abandoning the Black Baron persona, the fate of the competition remains unknown.
The ACES Semifinals was the first round of the ACES competition. This round would determine which team would qualify for the finals, provided which pilot from whatever team was left standing. Team Cooper faced off against Team Iceland and Team Belgium, with Sly as the main pilot. After Team Cooper pitted the two teams against each other, he was now given an advantage in this round, given how low their odds were. The winner here was Team Cooper.
The B-Champs round consisted of two teams dogfighting, not in the arena but above the main hub, around the castle. This took place during the Cooper Gang's heist, and it provided the perfect cover for Bentley's plan to get Sly to install tracking devices on Penelope's gunships without being detected. This is the only round Team Cooper did not take part in.
In the final round, the winner would be the one who manages to defeat the defending champ from the previous year. Team Cooper was up against Penelope, along with her team of flyers, but she was the only real target.
The award for the winning team was a gold trophy shaped like a biplane. It was first seen during one of Bentley's second slideshow in "Flight of Fancy," sitting on a table inside the hotel lobby. Bentley was seen holding it in the episode's epilogue when Team Cooper won the competition.
Team Iceland was one of two teams Team Cooper had to take down in the semifinals. They flew gray, tri-winged airplanes, plus they owned a trademark Viking helmet, which Sly stole from their hotel room to frame them for the destruction of the Belgians' prize plane. It was revealed by one of the pilots that Team Iceland sawed the landing gear off of Team Korea's planes.
Team Belgium was another team the Cooper Gang had to compete against during the semifinals. They flew blue, bi-winged airplanes that heavily resembled Sly's biplane. They owned a series of official gold-laced monogrammed handkerchiefs, one of which Bentley stole (with Murray's help) from a Belgian pilot to fulfill their plan to frame them for the theft of Team Iceland's lucky ice sculpture. Like Team Cooper, they owned a hangar, and on the inside, they initially had their prize plane sprung from the ceiling. The plane was eventually sabotaged by Murray in order to plant evidence that Team Iceland did it.
Team Canada was a minor team that participated in the competition. It was revealed by a pilot that they stole Team Ecuador's parachutes.
Team Korea was also a minor team that participated in the competition. They fell victim to the sabotage of their landing gear, courtesy of Team Iceland.
Team Ecuador was another minor team competing in the competition. As revealed by one of the pilots in the hotel, they had their parachutes stolen by Team Canada.
Team Portugal was another minor team mentioned by one of the pilots. They were responsible for putting rat poison in Team Muggshot's coffee machine.
Team Muggshot was the runner-up from the previous year's competition. Muggshot attempted to sabotage Team Cooper by sending out a squad of henchmen to destroy their plane and aircraft hangar. The threat was stopped thanks to Penelope's RC chopper. Muggshot was determined to emerge victorious in this competition, but thanks to the Cooper Gang getting him into a mix with Carmelita, he was eliminated and brought into custody.
Team Black Baron
Team Black Baron was the major opponent for Team Cooper in the ACES finals. While still under the Black Baron guise, Penelope commanded an enormous team of flyers and would even rely on a squad of blimp gunships if things were to go wrong. Penelope would not take so kindly to losing the competition, as she explained to her guards at one point (over the loudspeaker) that she would dismiss a lot of them and start clean with a new staff, should she lose the competition, while also making sure they remembered the rules of the competition.
Team Cooper consisted of Sly, Bentley and Murray. They owned a blue biplane that had a similar appearance to the Belgians' planes. Their goal was to defeat the Black Baron, not knowing it was Penelope all along. They also owned an aircraft hangar, where they stored their plane. Bentley took the liberty of installing security defenses around the building to help fend off any potential threats from other teams.
Behind the scenes
As seen in early screenshots for Sly 3, it was originally intended for Sly to compete against Team Muggshot during the competition, and he was to take down Muggshot himself.