The average starter in 2018 faces just 23 batters—the lowest total ever and the latest point in a decades-long decline. That number means a starting pitcher faces a lineup two and a half times, on average. Because teams know that starters tend to perform worse as they progress later into a game, it follows that they’d restrict those third-time-through-the-order matchups to the worse hitters at the bottom of a lineup, rather than the Mike Trouts and Justin Uptons at the top.
This is some very interesting managerial thinking outside the box. When debugging the dataset for tiering simulations I noticed an interesting trend in relief value. In the 70s teams had very negative value for relief squads as if they put all their washed up pitchers there. It started increasing early 80s and now average relief is very high.
On the todo list is an entry to present this data in some readable fashion that will contrast the graphs presented in this article. Until then ….