

This will vary because unlike other stat sites we include 100% of a brackets champions played and never include champions that don't belong in the bracket.
Emerald+ Champions Analysed: 16,590,402
We include 100% of the champions played of every selected tier bracket in our analysis, we never include champions from outside the tier quoted tier.


Karthus Counters
Karthus middle vs support Counters
Presently there is insufficent games played by Karthus middle on Patch 15.6 to determine the strongest support counters. A matchup requires a minimum of 100 games to be displayed.


Nami
the Tidecaller
Karthus wins against Nami 52.59% of the time which is 5.77% higher against Nami than the average opponent.
After normalising both champions win rates Karthus wins against Nami 3.20% more often than would be expected.
The average opponent winrate against Nami is 46.82%.


Lulu
the Fae Sorceress
Karthus wins against Lulu 52.83% of the time which is 5.67% higher against Lulu than the average opponent.
After normalising both champions win rates Karthus wins against Lulu 3.10% more often than would be expected.
The average opponent winrate against Lulu is 47.16%.


Karma
the Enlightened One
Karthus wins against Karma 56.14% of the time which is 6.81% higher against Karma than the average opponent.
After normalising both champions win rates Karthus wins against Karma 4.24% more often than would be expected.
The average opponent winrate against Karma is 49.33%.


Thresh
the Chain Warden
Karthus wins against Thresh 59.50% of the time which is 12.35% higher against Thresh than the average opponent.
After normalising both champions win rates Karthus wins against Thresh 9.78% more often than would be expected.
The average opponent winrate against Thresh is 47.15%.