The group stage of IEM Cologne 2025 marked the first major tournament following the return of Overpass to the active map pool — the map was added just a two week ago. We conducted a deep analysis of map pick rates, the number of bans, and side balance to understand how teams are adapting to the new conditions and which maps are becoming priorities. These data not only reflect the strategic preferences of teams but also allow us to predict potential trends in the playoffs, which begin on July 30, 2025.

Overview of the Map Pool
The most popular map of the stage was Nuke — it was played 10 times with 9 bans, making it the leader in terms of matches. Inferno also showed high popularity, played 10 times with 8 bans, indicating its stability in the rotation. Mirage, despite only 6 bans, was chosen 9 times, highlighting its strategic value. Dust2 was played 8 times with 9 bans, and Ancient 7 times with 13 bans, indicating its moderate popularity. Train, with only 6 matches and 13 bans, remains less appealing to teams. Overpass, with 3 matches and 14 bans, became the least used map, but its high number of bans suggests that teams are actively avoiding it.

Overpass, despite its recent addition to the active pool, immediately entered the rotation, though with a minimal number of matches. Its 14 bans — the highest among all maps — indicate high competition and a desire by teams to avoid it. Mirage, on the other hand, shows the minimal number of bans (6), underscoring its reliability and confidence in its selection. Nuke, with 9 bans, also remains popular, but its high number of matches (10) suggests that teams consider it a favorable arena for competition.

Side Balance
The best balance between sides was recorded on Inferno — the difference between CT and T wins here is minimal (50% CT, 50% T), making it ideal for fair competition. Nuke, on the contrary, shows the worst balance, where CT wins 62% of rounds, which may deter teams from choosing it for the T-side. Mirage, with 52% T wins, is the only map where the attack has a slight advantage, making it unique in the current map pool. Train also demonstrates a significant CT advantage (61%), which may be due to its challenging rotates for T. Dust2, with 55% CT wins, remains competitive but slightly favors defense. Overpass and Ancient show a similar balance (53% CT, 47% T), indicating their relative fairness, though with a slight advantage for CT.

These data reflect the evolution of team meta-strategies during the group stage and may influence map selection in the playoffs, which begin on July 30, 2025. Nuke, as the leader in terms of matches, is likely to remain a key arena, while Overpass, despite its recent addition, may get a chance due to team experiments.