Hello,… here is the popular one…
Barry Farmz Here – Comprehensive data driven farming guide for Season 3, Season 2, Season 1, Elemental Chests, Atlantis Rises, Missions, and more
EDIT: I missunderstand, I thought it was for the maps.
Monster, Raid, and Titan chest is completly random, and I think unfarmable item droprate is 1%.
Raid tournament reward based on rank, and it is available the help screen in the game play.
Other thing is elemental chest.
Elemental Chest Frequency - days tracking and results > estimated between 4 to 16 days