Our understanding of what it takes to win baseball games has undergone swift change in the past decade. Moneyball (2003) was a book about market inefficiency where the central insight was simple – the under-appreciated importance of walks in run creation. Analysts like Bill James challenged front offices and fans to rethink much of what we knew about winning games on a wide range of topics.
More recently, data collection in baseball has skyrocketed. The sport has moved from radar guns, to PITCHf/x (2008) and then Statcast (2015) — technologies now installed in every major league park. MLB collects and turns the data over to each organization.