Jarvan IV & Locke Synergy
Jarvan IV Jungle and Locke Mid win 51.1% of 2,442 Low Elo games together, +1.6 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
Jarvan gives Locke early gank and skirmish setup with his flag-drag knock-up, then Cataclysm confines a target so Locke can follow with his damage. A Locke pairing guide recommends keeping the mid wave on Locke's side to create repeat gank and chase windows, matching the duo's +1.6pp adjusted Low Elo edge.
Playing the duo
Jarvan IV's Dragon Strike(Q) to Demacian Standard(E) combo knocks an enemy up, and Cataclysm(R) creates an arena that can limit their escape while Locke follows with his Q and E damage.
How to play as Jarvan IV
Look for early ganks once you have Dragon Strike(Q) and Demacian Standard(E), and use Cataclysm(R) after level 6 to hold the target in reach of Locke's follow-up.
How to play as Locke
Keep your mid wave closer to your side when Jarvan is available to gank; the longer lane gives both of you room to chase after his flag-drag knock-up.
Sources
These notes come from Mobalytics, checked against the champions' abilities.