The Mapping Assistance Team (MAT) was a group responsible for assessing the quality of pending beatmaps and recommending them for ranking in the forum modding system. Their recommendations were passed on to the Beatmap Appreciation Team (BAT) by placing a proto-bubble, and the BAT would then make the final decision on whether the beatmap should enter Ranked.
The MAT were overseen by a MAT Leader who provided guidance and assistance where necessary.
The MAT was formed on the 27th of December, 2009, with initial members being hand-picked by members of the BAT.
Shortly afterwards, open applications were held, allowing all members of the general mapping and modding community to apply for a position in the MAT. On the 26th of February, 2010, the first new batch of MAT members were added from these applicants, based on a collective evaluation from members of the BAT and existing MAT. Further application cycles were held regularly to scout for new members, as well as provide feedback to unsuccessful applicants.
On the 4th of October, 2010, members of the MAT gained the ability to place full bubble and bubble pop icons on beatmaps, bringing their roles and responsibilities more into line with their BAT colleagues. However, they still did not possess forum or in-game chat moderation tools, and focused solely on evaluating and promoting beatmaps.
Following a gradual convergence of experience and responsibility between the two teams, on the 23rd of April, 2013, the MAT was dissolved, with all current members being promoted to the BAT and receiving the associated moderation tools and responsibilities.