It's all about leverage. Keep that in mind, as we take a look at why relievers, specifically closers,  are perhaps the most misused entity of a baseball team.

The refrain is oft heard: "Team Moneybags trades minor leaguer Johnny Prospect to Team Pauper for middle reliever, Senor Citizen." Why? Teams (such as our own) realize that the most readily available player at the trading deadline are relief pitchers. For filling such an in-demand role, this seemingly contradictory set of circumstances has often confounded me. What I've found to be one of the most basic things to understanding relief pitchers, and their role on a major league team, is that very few organizations value relievers correctly, or put them in situations that maximize their talents. One method of utilizing relievers that makes the most sense, is using relief pitchers, based on the leverage of a particular situation.

Typically, when a starter leaves a game, no matter what the situation, a "middle relief" pitcher will enter the game in his place. Whether runners are on base or not, these are the men that are most frequently given the task of either maintaining a lead, or keeping a game from getting out of hand. Relief pitchers are unique in that they are utilized in one role. Pinch hitters, for example, can get an infrequent start, or are part of a platoon of sorts. As for relievers, pitching after the starter has departed is the only role they serve on a team. This is mixed bag: on one hand, a good reliever can act as a secret weapon, ready to be deployed by a savvy manager whenever the time is right. On the other, their one dimentional talents result in these pitchers being among the cheapest veteran players, in terms of salary, and availability, in terms of being made availabe at trade deadlines, not having their contract re-newed, etc. This goes a long way to solving the paradox I mentioned at the beginning.

To my other question though, what does leverage have to do with the effective use of a bullpen? Leverage, has been defined by Tom Tango, as  a measure of how critical a specific batting situation is. (Source: Tom Tango). The game's score, the inning, and the runners on base are a few of the most relevant factors in determining the situational leverage of a particular point in a game. Beyond knowning when the highest leverage situation occurs, a manager has the difficult task of assigning a player to a role not knowing ahead of time how the game is going to turn out. Starting pitchers can prepare for days in advance of their appearance, but relief pitchers must be at the ready constantly. Or at least, most relief pitchers must be at the ready. A team's closer has over the years developed as much of a niche as any player in baseball. The closer is typically used to begin the ninth inning with no runners on, and no outs recorded. In 2004, 65% of closers saw their first action of the game in this very situation, the highest ever percentage. Why is this the case, is what I want to know.

For the most part, closers are used in this situation because it is the last chance for the opposing team to score run(s) in order to either prolong or win the game. On some level it makes sense for a manager to send his best arm out there as a "last resort" to save the win for his club. On another level though, it makes absolutely zero sense. This is a chart that outlines the expected run(s) for a given scenario of runner(s) on base and out(s) recorded. From that, we can see closers usually are used in situations where they are expected to give up a little more than half a run. The closer is assigned to prevent a team from winning in their last AB, "high stress" environment,this is one of the more easily wiggled out of situations a pitcher can face. The first link I supplied ya'll with is an article from The Hardball Times about relievers and the frequency that these pitchers are faced with higher than average leverage situations, with higher than average being any number above one on the "Leverage Index". Last season, 80%, 24 out of 30 clubs, utilized their relievers in leverage situations that were higher than average, when total reliever appearances were taken into account. We've established that closers at the most, face these more critical than average situations in 35% of their appearances, as they usually enter a game to pitch the ninth with no on/no out. This leaves the middle relief pitcher to face some of the most important challenges their team will encounter throughout a game. Most managers can assume that at some point in a game, their team, whether ahead or behind, will allow a couple of runners to reach base. Forget the score at this point- the team can't afford for any of these runs to score. It would make sense then, for a manager to approach this situation with leverage rather than routine in mind. Utilizing your closer at this point in the game, when the situational leverage is the highest, would be the most effective use of a closer/relief stud. A manager can preserve a close lead, keep a defecit from growing, or ensure that a tied ballgame stays that way. Nobody knows what the situation will be in the ninth inning. Allowing inherited runners to score before that, however, is a good way to ensure that a save situation doesn't arise for your team, no matter who's pitching.