What relief pitching is most important?

[Adam22]

I assume the closer is the most important, but then what? Are short relief and set up used in every game?

The long relief would be rarely used?

[takaplan]

It depends. Here is the breakdown of my bullpen, which has been the same the whole season. We have played 144 games.

Closer: 78 innings
Setup: 83 innings
Short Relief: 86 innings
Middle Relief: 65 innings
Long Relief: 52 innings
Spot Starter: 24 innings

Remember, these can be very different for different teams. However, I think that the Closer is most important, going down the list in order of importance, with the Long Reliever and Spot Starter being least important.