Heroes of the Storm game director Dustin Browder revealed in a BlizzCon panel that the development studio has acknowledged that the matchmaking algorithm, which was taken from Starcraft II, was essentially broken for a game that matched more than just two players.
According to Browder, the current matchmaking process for Heroes of the Storm was “too stressful” and “not very fun to play in”. The developer discovered that only 80 percent of players were getting even matchmaking, and 65 percent of games had players close to even character levels. Browder stated that not having 20% of the games with an even number of players on each side was in reality a 20% failure rate and unacceptable.
He went on to say that the matchmaking was taken from Starcraft II; the system was perfect for a game that was basically just one-on-one matches, but struggled to deal with a game like Heroes of the Storm which could feature a 5 vs. 5 battle. The algorithm relied on swapping players between matches to try to make even matches, and would end up failing in its effort to do just that.
Another major complaint of players was that even if they did well, the system would somehow give them a low ranked performance, and would find themselves inexplicably pushed back on the ladder ranking.
Browder promised that in the next few weeks, the game would be updated with a new matchmaking and ranking system that would rely less on swapping players and more on trying to build good matches through a better queuing algorithm.
Heroes of the Storm was launched back in 2 June 2015 as a free-to-play, microtransaction-driven game based on an all-star cast from Blizzard's game library. Critics gave it mixed reviews, praising its action but criticizing the poor gameplay balance and monetization model.