The majority of MLS teams play either a 4-2-3-1 or a 4-3-3. Just four of the 22 clubs — D.C. United, New England Revolution, San Jose Earthquakes, and Toronto FC — use something other than one of those formations as their main look. In addition, most teams have a fluid, varying tactical approach that is based around their best attacking players. I’ve seen very few teams come out with something noticeably different.
Colorado will sit deep and play narrow, the Red Bulls will press, TFC have their three-at-the-back, and NYCFC will play from the back at all costs.