With an all-time win rate of 41%, Io is the worst hero in Dota 2 for almost everyone.
Io the Wisp has the absolute lowest win rate of any hero in the history of Dota. According to Dotabuff’s win rate tracker, any team with Io wins just two out of every five matches. Wisp’s all-time low 41.05% win rate is a whopping 2.33% lower than the second-worst hero, Broodmother.
The same traits that give Wisp a terrible success rate in pubs also make it valuable in the pro scene. Wisp’s lowest pub win rate stretches back to Dota 2’s initial release in 2013. The lowest win rate hero is hampered by three factors.
Io’s 41% win rate comes from nearly a decade of data. The nature of Dota 2 pub communication works against Io as even with voice chat available, players tend to focus on their own game. The simple act of Tethering a carry relies on them listening and paying attention to comms and adjusting accordingly. It’s much easier to coordinate Overcharge timings and Relocate ganks in a tournament environment where all five players are on open mic.
Io is designed around the unique gimmick of sticking to another player and boosting their hero. Wisp’s kit doesn’t allow it to perform the same jobs as other supports. Io has no stun, no silence, and its slow is difficult to apply. Io can supply a lot of healing and Spirits provide an interesting way to scout surroundings but all in all, the lack of standard support tools contributes to Io’s bottom win rate.
Lastly, playing Io poorly is a very bloody affair. A solo Wisp is one of the most vulnerable heroes in Dota 2. A Lion or Disruptor can use their spells to escape enemies, but Tether’s range is short and, once again, relies on communication. For most pub players, just using Io’s ultimate to save a core is a death sentence. Most players haven’t practiced teleporting out of Relocate’s return. All of those problems combined make Io the least-winning hero in Dota 2 history.
Io may be reviled in public matchmaking, but it’s revered in the Dota 2 pro scene. Many of the negatives listed above either go away or become positives. Pro Dota 2 players have constant communication and are more experienced with each other’s playstyles. Both traits help the Io stay coordinated with its partner. The pro scene also highly values Relocate as a global initiation tool.
Io’s unique toolset also opens up room for experimentation. Anathan “Ana” Pham of OG took the world by storm with hard carry Io at The International 2019. Several pro players have experimented with other core roles as well as unique support builds. Wisp may not be a good omen in a pub match, but the unique kit makes Io an omnipresent force in the pro scene.