A few weeks ago I toyed around with a metric for comparing bullpen usage between teams. In that same post I highlighted a couple of relievers by plotting their pLI by appearance. Jeff Zimmerman took those second set of graphs and created a within-team usage comparison pair of charts (with some input from Tango) at Royal’s Review. Since then I’ve been pondering ways to quickly and graphically compare usage between teams. For a first attempt I narrowed the scope to just closer usage. My methodology was to bin each gmLI into one of four bins as specified by the below table
I then simply counted up the instances in each bin and charted the results. Here is the graph for the AL East, first with just raw totals
And then broken down by percentage
At first glance it looks like Mariano Rivera’s usage isn’t being optimized; however, these charts lack a team context. They don’t capture “attempts” or “chances”. I offer the following chart that takes the max reliever gmLI for each team game played and bins them in the same bins. I think ideally a chart that somehow combines these charts would tell the best story. Note, this chart is a little dated as this article has been in the works for awhile. It portrays the point though still.
Taking all of the charts in, it appears that Papelbon has been “wasted” the least in low leverage situations, while the rest have all spent a decent (30-50%) amount of time in either low or medium leverage situations.