Dota 2 announced that it released an update which now allows both 3-person parties and 2-person parties to match with a 5-stack on occasion, particularly if the need is high. This change was implemented after it was found out that there were cases where three person parties had problems finding compatible players.
Back in September, Dota 2 announced that it was making changes to matchmaking with the new ranked season. Changes include offering a Role Symmetry and even coming out with a Draft Role Report. The update also introduced the idea of Core and Support Ranks. The September update caught the eye of the Dota 2 community, especially with the portion on the Ban Wave. The first ban wave was focused on players that had exceptionally low behavior scores and regular bans were made for users who fall into this small percentage of the community. The second was on players who were found out to have violated the Steam Service Agreement. Of course, players caught using exploits to get the advantage also were banned.
Going back to the Matchmaking system, Dota 2 again released an update fixing the issues that resulted from the September update. One of this was the Matchup Combinations.
The October update ruled that five-player parties could only be matched against other five-player parties, without any consideration to matchmaking conditions. At this time, Dota 2 developer Valve said in a post that they "were unsure if an absolute requirement like this will result in net higher quality matchmaking due to the more limited opponent spectrum available in that case, but we know this is an aspect the community talks about often and we are going to do our best to work within those constraints."
In addition, solo players were going to be considered for matches against at most one party of two. What this meant was that a solo player could only be matched against a team of five solo players or against three solo players and a party of two.
As mentioned earlier, this resulted in three-player parties being unable to find matches. Specifically, a three-person party was not allowed to match against a five-stack or five solos. While fighting against solos resulted in a much bigger spectrum of compatible matches, it was clear that it wasn't desirable to some players.
With this new update, hopefully players are going to get matched against other teams faster regardless of how many players are in a party.
