Fizz vs Master Yi Jungle Matchup
Fizz Jungle wins 48.9% of 548 Low Elo games against Master Yi Jungle, -0.4 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 Fizz
Do not throw Chum the Waters(R) from range while Yi still has Alpha Strike(Q) or Meditate(W) ready; bait one defense or have an ally's crowd control hold him first.
Track Yi with vision and avoid a fair solo duel once he has scaled; Fizz players recommend disrupting his early farm before he reaches his later power spikes. (Unverified: no source confirms this note.)
Alpha Strike(Q) can make Master Yi untargetable, while Meditate(W) reduces incoming damage; both can blunt Fizz's Chum the Waters(R) burst.
How to play as Master Yi
Save Alpha Strike(Q) to avoid Fizz's fish, or use Meditate(W) as the shark damage lands; Fizz players identify both spells as ways to blunt his all-in.
Sources
These notes come from r/fizzmains, checked against the champions' abilities.