Hecarim & Nami Synergy
Hecarim Jungle and Nami Support win 51.1% of 2,044 Low Elo games together, +1.3 points vs expected, 2-patch window 26.19-26.20.
Researched on LoL patch 26.20. Tips are written to hold at any rank; stats come from Low Elo ranked games up to patch 26.20.
Why this duo works
Nami's movement-speed buffs feed Hecarim's P for bonus attack damage, and her wave adds a slow and knockup to his charge. Hecarim players specifically call Nami a useful enchanter for the speed and utility she gives him.
Playing the duo
Nami's P gives allied champions movement speed when her abilities hit them, and R doubles that effect for allies hit; Hecarim's P converts bonus movement speed into attack damage.
How to play as Hecarim
Coordinate your E or R entry with Nami's speed buff or wave; movement speed raises your P attack damage, while her knockup and slow make it easier to keep your target in the fight.
How to play as Nami
Aim R through Hecarim as he charges so he gets the doubled Surging Tides speed bonus while enemies are knocked up and slowed; E him before his follow-up attacks for extra damage and a slow.
Sources
These notes come from r/HecarimMains, checked against the champions' abilities.