How to counter Darius
Let us take a look on how to beat Darius. We will look at champions who are strong against Darius and who are weak against Darius. Use win rate, gold difference and creep score difference at minute 10 to find the best 
Top champion who counters Darius. You can already win in champion select with the right counters for Darius. If you want to know how to counter Darius then you need to take into account the best picks vs Darius and the worst picks vs Darius. This Darius 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 Darius or whether they played as Darius.
Champions used by Pros to counter pick Darius
Looking at the matches from Pros (see table Pros counter picked Darius) we can see that they picked 
Rumble most often to counter pick Darius. The matchup Rumble vs Darius occured 19 times. Darius has 11 wins and 8 losses in this matchup. Learn how to counter pick Rumble to get another perspective on the data.
Lane outcome for Darius
When looking at Darius 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 Darius. The lane outcome of Darius consists of three outcomes: Win, Loss or Draw. Let's take a look of Darius 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 Darius.
Conclusion
Analyze the available data and learn how to beat Darius. To master Darius take also a look on Darius builds and runes for Darius. Good luck, Summoner!