How to counter Blitzcrank
Let us take a look on how to beat Blitzcrank. We will look at champions who are strong against Blitzcrank and who are weak against Blitzcrank. Use win rate, gold difference and creep score difference at minute 10 to find the best 
Support champion who counters Blitzcrank. You can already win in champion select with the right counters for Blitzcrank. If you want to know how to counter Blitzcrank then you need to take into account the best picks vs Blitzcrank and the worst picks vs Blitzcrank. This Blitzcrank counter data is based on matches played by Pros on patch 14.23 and previous ones. It is important to see whether Pros counter picked Blitzcrank or whether they played as Blitzcrank.
Champions used by Pros to counter pick Blitzcrank
Looking at the matches from Pros (see table Pros counter picked Blitzcrank) we can see that they picked 
Thresh most often to counter pick Blitzcrank. The matchup Thresh vs Blitzcrank occured 23 times. Blitzcrank has 13 wins and 10 losses in this matchup. Learn how to counter pick Thresh to get another perspective on the data.
Lane outcome for Blitzcrank
When looking at Blitzcrank 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 Blitzcrank. The lane outcome of Blitzcrank consists of three outcomes: Win, Loss or Draw. Let's take a look of Blitzcrank 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 Blitzcrank.
Conclusion
Analyze the available data and learn how to beat Blitzcrank. To master Blitzcrank take also a look on Blitzcrank builds and runes for Blitzcrank. Good luck, Summoner!