Master Yi vs Jarvan IV Jungle Matchup

Master Yi Jungle wins 54.2% of 3,637 Low Elo games against Jarvan IV Jungle, +2.5 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 Master Yi is favored

Master Yi can use Alpha Strike(Q) to avoid Jarvan IV's Dragon Strike(Q) plus Demacian Standard(E) knockup, then punish after Jarvan has spent his burst; Jarvan's best chance is to turn early ganks into a map lead instead of taking a fair duel.

Measured in High Elo: Master Yi wins 1.6pp more often than expected over 1,253 games.

How to play as Master Yi

Hold Alpha Strike(Q) for Jarvan IV's flag-and-drag combo instead of using it to open; keep Wuju Style(E) ready for the fight rather than activating it before you reach him.

Alpha Strike(Q) can dodge Jarvan IV's Dragon Strike(Q) and Demacian Standard(E) combo, while also giving Yi a way to leave Cataclysm(R) by targeting a nearby unit.

Jarvan IV's early gank setup is stronger than his straight duel into Yi, while Yi's Wuju Style(E) adds true damage to repeated attacks once he can stay on the target.

How to play as Jarvan IV

Do not build your plan around beating Yi in an early 1v1; gank lanes and use map tempo to get your team ahead before he reaches his power spikes.

Sources

These notes come from r/YIMO and r/Jungle_Mains, checked against the champions' abilities.