How Andrew Miller impacts the Cleveland Indians bullpen

The Cleveland Indians may hold a sizable lead in the American League Central and have a shot at the American League's best record by season's end, but they are not a roster without holes. Their two biggest holes -- catcher and left-handed relief -- were both addressed at various points of the busy deadline weekend, but only one trade actually went through, as Jonathan Lucroy prepares to rot in the Texas heat and Andrew Miller became a member of the Indians.

Before we get to what Miller can bring, let's take a painful look at what the bullpen was before the Indians traded their top overall prospect and three prospect arms to fix it.

Prior to last night's game against the Minnesota Twins, the Indians used 20 relief pitchers in their 102 games, including two shutout innings from catcher Chris Gimenez. Combined, they ranked 11th in the AL in FanGraphs WAR (1.8) and they had the third highest walks per nine (3.56) among AL relievers. Curiously enough, in high leverage situations, Indians relievers have actually given up the fewest hits in the AL (69), but the fifth most home runs (11). Translation: When they were bad, it hurt.

Cody Allen has been the team's closer for three seasons now, and based on Miller's appearance in junk time last night, I get the feeling Terry Francona is going to stick with that. That's a good decision.

From a pure baseball standpoint, bullpen roles are pointless. Your best reliever should be going into a game with the game on the line in the highest leverage situation, period. Rarely is that in the ninth inning with your team up by three and the bases empty for an easy save. But baseball is a game with people, and a lot of those people need certainty and routine to keep performing well. If Tito chooses to keep Allen in the closer role -- a role he has been great in over the past three seasons -- it will allow him to use Miller in the higher leverage situations, whenever they occur.

Ever since his transition to a full-time reliever in 2012, Miller has been one of the best in the game, no matter what situation he pitches in. Only a handful of relievers have a better ERA over that span than Miller's 2.24 and only three (Craig Kimbrel, Dellin Betances, Aroldis Chapman) have more strikeouts per nine than Miller's 14.17. He has been incredible over his 240.2 innings of relief in the last four seasons.

Miller keeps up this success with a fastball that sits in the 94-96 range and a devastating slider that opposing batters are all but helpless against. In 2013, the year in which his slider was at it's "worst", opposing batters hit .200 against it. That batting average against plummeted to .082 in 2014 and .093 in 2015. So far in 2016, opposing batters are still struggling against it with a .191 average.

The nastiness of Miller's slider was on display early this season, as seen in his very first appearance of 2016 when he was called upon to close against the Houston Astros on April 7, courtesy of The Pitcher List.

Das nasty.

Getting back to the all-important high-leverage situations, Miller's FIP has never climbed over 2.05 in any year since becoming a reliever in high-leverage situations, and he strikes out over 40 percent of the batters he faces with the game on the line. If last night's appearance was an indication of how Tito plans to use him, that means he can come into the game with runners on base and dominate, as opposed to entering the ninth inning for a token save. Based on how much Francona seems to love four-out saves, Miller could be getting a few of those as well -- coming into a dangerous situation to end the eighth then staying in the game to coast in the ninth.

No matter how he gets used, Miller's impact on the Tribe's bullpen should be evident, even in the regular season. They went from having a pretty great closer and a bunch of who-knows-what in the bullpen, to having one of the best relief arms in baseball available in any situation. Over the course of this next half-season, that might only be 20-30 innings, but the real test will be in the playoffs with everything on the line in an elimination game. Instead of Bryan Shaw, Dan Otero, or Zac McAllister warming in the pen, it'll be Andrew Miller. That's a good feeling to have down the stretch.

And even beyond that, the Indians will have Miller for a full two more seasons. The Indians picked up all of his remaining contract -- $9 million per season -- and they will have him under control through his 33-year-old season. Anything can happen with a pitcher, but they could reasonably expect to get elite-level performance for those two years with the best-case scenario being the opportunity to flip him in the second-half of 2018.

But that's a long ways away. For now, enjoy Miller Time when it matters most.