How to counter Udyr
Let us take a look on how to beat Udyr. We will look at champions who are strong against Udyr and who are weak against Udyr. Use win rate, gold difference and creep score difference at minute 10 to find the best 
Top champion who counters Udyr. You can already win in champion select with the right counters for Udyr. If you want to know how to counter Udyr then you need to take into account the best picks vs Udyr and the worst picks vs Udyr. This Udyr counter data is based on matches played by Pros on patch 15.12 and previous ones. It is important to see whether Pros counter picked Udyr or whether they played as Udyr.
Champions used by Pros to counter pick Udyr
Looking at the matches from Pros (see table Pros counter picked Udyr) we can see that they picked 
Rumble most often to counter pick Udyr. The matchup Rumble vs Udyr occured 3 times. Udyr has 1 wins and 2 losses in this matchup. Learn how to counter pick Rumble to get another perspective on the data.
Lane outcome for Udyr
When looking at Udyr 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 Udyr. The lane outcome of Udyr consists of three outcomes: Win, Loss or Draw. Let's take a look of Udyr 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 Udyr.
Conclusion
Analyze the available data and learn how to beat Udyr. To master Udyr take also a look on Udyr builds and runes for Udyr. Good luck, Summoner!