Nami Support vs Katarina ADC Matchup

Nami Support wins 52.9% of 408 Low Elo games against Katarina ADC, +0.8 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 Nami

When Katarina starts Death Lotus(R), cast Aqua Prison(Q) or Tidal Wave(R) early to interrupt it; waiting until she has dealt damage can leave too little time for either spell to reach her.

Take Exhaust and use it when Katarina commits to her all-in; support players specifically recommend exhausting her as she goes in.

Aqua Prison(Q)'s stun and Tidal Wave(R)'s knock-up can interrupt Death Lotus(R); a Nami player warns that both spells can arrive too late if she waits for Katarina to deal damage first.

How to play as Katarina

Bait out Nami's Aqua Prison(Q) or Tidal Wave(R) before channeling Death Lotus(R); support players warn that saving crowd control for her ultimate can shut down her all-in. (Unverified: no source confirms this note.)

Sources

These notes come from r/supportlol and LoL Wiki, checked against the champions' abilities.