Best RP skill sets (by K%-BB%) through May.

A look at teams with K%-BB% challenged closers: BOS, CHW, CLE, COL, and TAM.

A look at roles in BAL, MIA, ARI, HOU and MIN pens

This column takes Tom Tango's "Leverage Index" ("LI") and clean appearances versus total appearances as usage indicators to examine versus the typical skills indicators (xERA, WHIP, K%, K%-BB% and importantly, still projections of those skills indicators) to make calls on where fluid pens are headed. The column covers DET, PHI, NYY, CHC, WAS, and OAK pens.

Best skills by relevance and K%-BB%. Then, the ones that are sustainable by projection.

This column examines the early work in the Cubs, Tigers, Astros, Marlins, Giants, Rays, and Rangers pens and compares that work to the projected skills.

A look at COL, KC, LAA, NYY, PHI, and WAS pens

A simple skills filter gives us some good names to review.

Making sense of the 38 relievers who successfully closed a game the first week.

Opening Day usage around the league.

Spring observations focused on the Tigers, A's, Angels and White Sox pens.