MacroMind matchup data — real ranked games, not opinions
Karthus vs Rengar
In Jungle, Karthus wins 52% against Rengar across 346 observed ranked games. This is an observed win rate shown with its sample size, not a prediction or a guaranteed counter.
By 15 minutes the median game has Karthus ahead by 111 gold.
Does Karthus counter Rengar?
The numbers call it close: 52% for Karthus over 346 games, inside the noise band. Pick the side you play better.
How to beat Rengar as Karthus
Turn the early game into gold: 300 up at 10:00 runs this matchup at 59% over 174 games; 300 behind drops it to 46% over 171.
The median first death in this lane comes at 4:07; the level 6 spike lands around 6:45. Respect the all-in window until your spike is online.