In the list of Public lobbies, there is a column with the tile Match Quality, and under it you can see some checkmarks.

A lobby gets more checkmarks if:

• The lobby is stable: players are able to join it without connection errors
• Matches are played until they end, instead of the Host returning to the Treehouse before there is a Winner or a Draw

A lobby loses checkmarks if:

• It contains players that are away or inactive (AFK)
• Many people have been kicked since the lobby was made