As an advanced stats geak it's really simple. If you look at statistics steals and blocks are the least likely stats to happen, followed by turnovers, assists and rebounds. Each stat has a point value tied to it. When he did his analysis he determined what directly lead to points. You can't score without possessions. Steals and blocks add possessions to your team and opportunities for easy baskets. Turnovers take possessions away from you and lead to easy baskets. Assists are mostly just a by product of scoring. Some players are better passers, but it's easier to replace assists and rebounds because shots will always be made and missed , that's what basketball is. This is how the Oakland A's were able to compete in the early oughts. People will find fault with any statistical measure, and for what it is worth Tyler Ennis lead our team in win shares this year, ironically followed by Trevor Cooney. Supposedly they added the most value to our team by statistical measures.
By advanced statistical measures we had three players last year outperform our entire team this year, and a fourth player from last year outperformed everyone but Ennis this year,
so advanced statistics show that we were a better team last year compared to this year, especially the core four of mcw, southerland, fair, and triche. Advanced statistics show also that cj was much better last year compared to this year. I know people will argue that it doesn't take into account a players role on the team or variance in performance, but their is no doubt it is a great measure in analyzing the quality of a team.
http://www.sports-reference.com/cbb/schools/syracuse/2014.html