Last year, here at Fantasy Alarm, Greg Jewett and I released a new metric to judge relievers and just how good a job they were doing in their roles for their teams. The idea was born out of our want to cut out all of the noise created by Holds and Saves and K/9 that relievers are almost always judged by because those are the only well-known counting stats for fantasy players to use to assess a reliever's value for their fantasy team. However, that doesn’t help to understand the relievers that are actually performing well in their roles for their teams regardless of counting stats and it also doesn’t usually explain why managers use certain guys in certain situations as compared to others. The other thing we were trying to remove from the cloudiness of reliever numbers is the luck that is involved in their counting stats. A perfect example of this was the beginning of the year with Kirby Yates. Even though he was leading the league in Saves from the get-go, he wasn’t doing it efficiently as he was walking a bunch of guys and allowing hits and then managing to work his way out of it. All you as a fantasy player would see is that Yates was leading the league in saves without knowing how lucky he was really getting to still have that many saves and not have blown a bunch early on. However, with the Reliever Efficiency Rate, you can surmise exactly that and who may be next in line in high leverage spots for each team.
We are now going to be re-releasing it this year and updating it each Monday, through the previous Friday’s game. It should give FANation a new way to look at relief pitchers and with the team rankings, that take into account the total RER for each pitcher they’ve used in relief to that point in the season, DFS strategy could be helped as you can target certain teams with worse bullpens for point-scoring opportunities later in games.
Breakdown Of How R.E.R. Is Calculated
Using some advanced Win Probability stats like Shutdowns, Meltdowns, and leverage situations we can arrive at an RER for each pitcher that has come in in relief. Shutdowns and Meltdowns are given each time a reliever has added or subtracted six-percent to the team's win probability during the course of their outing. However, because not all of those situations are equal, we factor in leverage which is measured based on the game situation in terms of lead, runners on base, where in the order they are, and pitch count. There is also a factor of run prevention in the stat that gives credit for pitchers who allow fewer runs in higher leverage situations and take away credit for those that allow more runs in lower leverage situations. All of these stats are situation-specific so the exact role in the bullpen doesn’t matter as much as a closer can face a low-leverage situation but a middle reliever can face the highest-leverage situation in the game and so both pitchers will get proper credit for fulfilling or not fulfilling their roles in those spots. Also taken into account are innings pitched and games appeared in but it’s not always the case that just because a pitcher has more innings or games that their R.E.R. will be higher.
The Reliever Efficiency Rate is cumulative throughout the season, meaning each week a pitcher’s number could rise or fall and by season’s end the top pitchers number’s will be much higher than their original marks simply because with more innings and games come more chances to improve or impair their R.E.R.
The Reliever Efficiency Rate works on a scale that is an average of each week of the regular season that pitcher pitched in.
Player Rankings
Below is the top-105 relievers to this point in the season. You may notice right off the bat (excuse the pun) that the top closers aren’t necessarily in the top spots as Trevor Rosenthal and Kenley Jansen are the highest ranked pitchers among the top-10 in saves. This just brings out the point of this metric in determining who is actually doing their job on the mound and who is skating by because of luck.
No pitcher is in the Elite category just yet but Jordan Romano has had two of his four weeks crack the 1.2 mark and in fact there have only been six individual weeks of 1.1 marks or better this year as 2020 continues to be an odd year all around.
Team Rankings
The team rankings come from adding up every pitcher’s RER from that team who has pitched the requisite number of innings (.3 innings per team game played) and then adding those up each week and averaging them across the weeks. The higher the Avg. R.E.R. is, the better the total bullpen has been to this point in the season and while the ranges from above don’t necessarily hold for the team rankings, the general rule of thumb is that anything over 2.0 is Elite, 2-1.5 is great, 1.0-1.5 is above average, .5-1.0 is average, and less than .5 is poor. Again these rankings can help in DFS a bit as bullpens become more prevalent in games at this point.