How to counter Soraka
Let us take a look on how to beat Soraka. We will look at champions who are strong against Soraka and who are weak against Soraka. Use win rate, gold difference and creep score difference at minute 10 to find the best 
Support champion who counters Soraka. You can already win in champion select with the right counters for Soraka. If you want to know how to counter Soraka then you need to take into account the best picks vs Soraka and the worst picks vs Soraka. This Soraka counter data is based on matches played by Pros on patch 14.22 and previous ones. It is important to see whether Pros counter picked Soraka or whether they played as Soraka.
Champions used by Pros to counter pick Soraka
Looking at the matches from Pros (see table Pros counter picked Soraka) we can see that they picked 
Senna most often to counter pick Soraka. The matchup Senna vs Soraka occured 11 times. Soraka has 8 wins and 3 losses in this matchup. Learn how to counter pick Senna to get another perspective on the data.
Lane outcome for Soraka
When looking at Soraka 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 Soraka. The lane outcome of Soraka consists of three outcomes: Win, Loss or Draw. Let's take a look of Soraka 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 Soraka.
Conclusion
Analyze the available data and learn how to beat Soraka. To master Soraka take also a look on Soraka builds and runes for Soraka. Good luck, Summoner!