How to counter Briar
Let us take a look on how to beat Briar. We will look at champions who are strong against Briar and who are weak against Briar. Use win rate, gold difference and creep score difference at minute 10 to find the best 
Jungle champion who counters Briar. You can already win in champion select with the right counters for Briar. If you want to know how to counter Briar then you need to take into account the best picks vs Briar and the worst picks vs Briar. This Briar counter data is based on matches played by Pros on patch 15.14 and previous ones. It is important to see whether Pros counter picked Briar or whether they played as Briar.
Champions used by Pros to counter pick Briar
Looking at the matches from Pros (see table Pros counter picked Briar) we can see that they picked 
Lee Sin most often to counter pick Briar. The matchup Lee Sin vs Briar occured 4 times. Briar has 2 wins and 2 losses in this matchup. Learn how to counter pick Lee Sin to get another perspective on the data.
Lane outcome for Briar
When looking at Briar 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 Briar. The lane outcome of Briar consists of three outcomes: Win, Loss or Draw. Let's take a look of Briar 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 Briar.
Conclusion
Analyze the available data and learn how to beat Briar. To master Briar take also a look on Briar builds and runes for Briar. Good luck, Summoner!