How to counter Ekko
Let us take a look on how to beat Ekko. We will look at champions who are strong against Ekko and who are weak against Ekko. Use win rate, gold difference and creep score difference at minute 10 to find the best 
Mid champion who counters Ekko. You can already win in champion select with the right counters for Ekko. If you want to know how to counter Ekko then you need to take into account the best picks vs Ekko and the worst picks vs Ekko. This Ekko counter data is based on matches played by Pros on patch 13.24 and previous ones. It is important to see whether Pros counter picked Ekko or whether they played as Ekko.
Champions used by Pros to counter pick Ekko
Looking at the matches from Pros (see table Pros counter picked Ekko) we can see that they picked 
Orianna most often to counter pick Ekko. The matchup Orianna vs Ekko occured 13 times. Ekko has 5 wins and 8 losses in this matchup. Learn how to counter pick Orianna to get another perspective on the data.
Lane outcome for Ekko
When looking at Ekko counters you will notice that win rates alone are not conclusional. Therefore we provide an overview (see table Lane Outcome) where you can see the lane outcome of Pros who played Ekko. The lane outcome of Ekko consists of three outcomes: Win, Loss or Draw. Let's take a look of Ekko lane and match outcome for specific matchups. Considering the lane outcome and the match outcome of a specific matchup, might enable you to find the right counter for Ekko.
Conclusion
Analyze the available data and learn how to beat Ekko. To master Ekko take also a look on Ekko builds and runes for Ekko. Good luck, Summoner!