Senna Probuilds explained
Based on our LoL Support Tier List from pro builds at patch 14.23, 
Senna – the Redeemer – is a S-Tier champion. Among professional League of Legends players, Senna is most often selected on the 
Support position. This is your source to learn all about Senna Probuilds and to learn how to play Senna. This page shows you how a pro builds Senna in detail. Solo queue and tournament matches played by the best Senna players are listed.
On the current patch pros on Senna have won 22 out of 39 matches, resulting in a win rate of 56.4% and a pick rate of 0.6%. In 1.1% of the matches Senna is banned, because it can be very unpleasant to have to play against the 
Support. When Senna is not banned and only the Senna Probuilds are considered, the champion averages a KDA of 0.0 in professional players Solo Queue matches.
A Senna probuild is best suited to counter Swain, to counter Rell or to counter Alistar on the opposing team. With Senna and the available probuilds, it is possible to minimize their strengths and exploit their weaknesses. On the other hand, 
Lux, Nami or Vel'Koz lead to desperation for Senna players. Learn from Pros how they counter pick Senna.
In regards to runes for Senna you can see that 
Resolve and 
Precision are the rune paths, which are preferred by Pros.
FAQ for Senna Probuilds
On which position do the most Senna Probuilds exist?
Pros play Senna mostly on position Support.