As there won’t be more updates for the last moments of 2020, is time to rank what buffs/nerfs were the most notable and with high impact (2019 December patch doesn’t count since is more like a fixing patch):
Top 10 nerfs:
10.Battle Elephant multiple nerfs of July and November (Being too dominant in teamgames requiered considerable nerfs, but still very strong).
9. Aztec military creation bonus reduced to 11% introduced in May (The beginning of the fall of the Aztec dominance in pro games).
8.Lithuanian Leitis PA reduction introduced in November (The mighty Leitis finally found their first hit that made them more vulnerable).
7. Khmer nerfs of April (The dominant civ finds a strong hit to their military against Halb +SO)
6. Goths multiple nerfs of March and November (Most strangely managed civ by FE)
5. Persian lost of the 5% workrate in Darkage since April (The new S tier civ was killed)
4. Celts loss of the infantry speed in darkage (Thanks Hoang)
3. Indian changes fo the PA and the reduction of the extra attack vs buildings (Most hated Camels messed up their reign in teamgames and then weaker against archers).
2. Khmer major nerfs of November (Powerful Khmer reign in teamgames seems to be over, for now).
Honorable mentions: Indian fishing bonus reduction of April, Bulgarian loss of Paladin in April, Chinese loss of Redemption of March, Vikings Chieftans cost increase of November.
1: Aztec villager carry cap of November: 20 years of the Aztecs in the S tier side of most maps and tournaments is largely destroyed, especially to their farmers.
Now the top 10 buffs:
10. Vietnamese new bonus of economic upgrades no costing wood introduced in February (A new bonus that turned them into a more usable civ, but still hard to manage).
9. Burmese Arambai wood cost reduction of January (Just a strong buff to a hated unit in Arena)
8. Chinese access to Block Printing (Say hi to the Historical Accuracy, but broke them vs Siege).
7. Lithuanians buffs of April (Finally the Leitis made it to be viable and strong, and Tower Shields being a worthy tech).
6. Tatars buffs of March (Everything being strong buffs and Happy Tamerlane noises with: SEND FORTH THE FLAMING CAMELS).
5. Bulgarians/Portuguese/Koreans buffs of November (a huge update boosted all these from the weaker side to the strong and mainstream side of the game, hugell¿y discussed here for months.
4. Teutons buffs of February and April, especially to their new melee armor bonus (a civ that all love due to their strong theme of slow but armored army, and a faster Teutonic Knight).
3. Goths free loom introduced in April (finally had a strong eco bonus but turned them into a laming civ).
2 Tatars new bonus of extra sheeps and Silk Armor with the extra melee armor introduced in November (The recent new S tier civ of Arabia and new strong civ in Booming, the start of the Tatars hegemony).
Honorable mentions: New Cumans bonus of Capped Ram in Castle age, Steppe Husbandry and Silk Armor affecting Steppe Lancers of March, Stirrups including Knights in April, Elephant Archer buffs of May, Byzantine Cataphract upgrades cost reducton/Portuguese and Koreans minor buffs and Pavise affecting Condottieri in July, New extra PA for Turkish Light Cavalry/Jaguar Warrior training time buff/Shotel Warrior gold cost reduction of November.
1. The new Khmer Farming bonus of not needing dropsites introduced in January: A funny bonus that turned them into a competent civ in every regard, plus being the most hated civ in all teamgames due of this and their Elephants, main ban in some tournaments.