Briar vs Jarvan IV Jungle Matchup

Briar Jungle wins 52.0% of 1,997 Low Elo games against Jarvan IV Jungle, -0.2 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.

How to play as Briar

Don't chase Jarvan while Dragon Strike(Q) and Demacian Standard(E) are both ready; sidestep the knockup or let him spend the combo, then take the close fight while his engage is down. (Unverified: no source confirms this note.)

Dragon Strike(Q) plus Demacian Standard(E) gives Jarvan a knockup engage, while Briar can end Blood Frenzy(W) with Chilling Scream(E) and turn the close-range follow-up into a wall stun if terrain is nearby.

Cataclysm(R) traps Briar in close quarters, where Jarvan can keep fighting; Briar's self-healing and E shove give her a way to sustain and create space if he commits alone. (Unverified: no source confirms this note.)

How to play as Jarvan IV

Use your E-Q engage with teammate follow-up, and save Cataclysm(R) until Briar has spent Chilling Scream(E); otherwise she can end Blood Frenzy and create space before your team finishes the target.

Sources

These notes come from r/BriarMains, checked against the champions' abilities.