There have certainly attempts to apply statistics and machine learning towards drafting teams in Dota 2. [1]
Alan "Nahaz" Bester does a lot of statistical analysis of Dota 2 games. Search for some of his lectures on YouTube. [2]
Sources and References:
[1] Conley, Kevin, and Daniel Perry. "How does he saw me? A recommendation engine for picking heroes in Dota 2." Np, nd Web 7 (2013).
[2] Ciubotaru, Andra. “Nahaz Interview: Balancing Dota, Family Life and Academia.” Dota Blast, 23 Jan. 2016, dotablast.com/nahaz-interview-frankfurt-major-dota-family-life-academia/.