Among the various rule changes put in place for the 2020 season, if and when that actually gets started, the one that's drawn the most attention is the edict that all pitchers must face at least three batters (or pitch to the end of an inning), with the only exception being injury or illness. The idea behind it is simple, really. It's not meant to shorten games, because it probably won't shorten games. It's meant to minimize dead time, the interminable delays resulting from a manager interrupting play to walk to the mound, signal for a reliever, and have that pitcher enter and warm up.

It doesn't eliminate strategy, as some have suggested, because honestly it doesn't take all that much thought to say "a lefty is hitting, go call in the lefty" in the first place. It might actually add some interesting new strategy. It won't, honestly, probably make all that much of a difference at all, because it just doesn't happen that often.

But for some individual pitchers, it could mean everything. Lefties who traditionally only face one hitter and leave -- the LOOGY, or Left-handed One Out Guy -- might find it more difficult to stick on a roster, since now they'll be exposed to righty hitters too.

All that said, we'll admit we were stunned when MLB.com's Mandy Bell spoke to Cleveland lefty Oliver Pérez and righty Adam Cimber about what their lives would be like when they have to face multiple batters. Rather than dread it, they claim to look forward to it.

"Now, I understand I have to pitch to three guys," Pérez said. "You might feel more comfortable because you have to pitch to three guys and that’s something that’s better. Probably less pressure.”

“One hundred percent,” Cimber agreed. “I’ve felt that way, too. I think when I came over to Cleveland and Tito was using me more as a matchup guy -- whereas in San Diego I was going two to three innings at a time -- I did put a little bit more pressure on myself to get righties out. Like, ‘Oh, this is my job to get righties out.’ When I think, ‘Yeah, I’m going to be out there righty, lefty, I’m just going to get guys out,’ it does take a little bit of pressure off.”

So maybe they're not actually that worried about it. But on the other end, there are some pitchers who are going to be more valuable, the ones who can consistently pitch to three or more batters and retire hitters from both sides of the plate. Those guys were always useful, and now they may be even moreso. How do we find those relievers?

It's actually harder than it seems. There isn't one right way to do this. Instead, we'll approach this problem from a few different ways, and see if there are pitchers who appear via multiple methods. There's a risk here that we're just going to end up with "the best relievers anyway," like Josh Hader or Kirby Yates, but value is value.

(For each list below, we've removed pitchers who aren't currently with a team, or due to outside factors like injury or other reasons almost certainly won't be available in 2020.)

The first place to start is to find which pitchers most often did face three batters. Even that isn't perfect -- just because, say, a lefty like Adam Kolarek rarely faces three batters doesn't mean he can't -- but we have to work within what we've seen.

1) Percent of relief appearances that went 3+ batters
2018-'19, minimum 40 total relief appearances

100.0% Arodys Vizcaíno
98.5% Shane Greene
98.1% Luis Cessa
98.0% Josh James
97.9% Taylor Cole
97.8% Ryan Yarbrough
97.7% Jalen Beeks
97.7% Craig Kimbrel
97.6% Clay Holmes
97.6% Blake Treinen
97.6% Tyler Thornburg
97.6% Hansel Robles

That's an interesting top 10, if maybe not a satisfying one. It's full of sometimes-great closers like Kimbrel and Treinen, swingmen like Cessa and James, and some Rays caught up in being bulk guys after openers in Yarbrough and Beeks. You definitely know which teams Cole and Holmes are on, right? As long as there are no further questions: Yes, we all definitely do.

But that's not good enough, because we need performance, not just frequency. Now, let's do that same thing, just this time we'll rank it by best performance (via wOBA) within only those three-plus appearances.

2) Lowest wOBA in relief appearances that went 3+ batters
2018-'19, minimum 40 total relief appearances

.222 -- J.B. Wendelken
.231 -- Josh Hader
.236 -- Kirby Yates
.240 -- Giovanny Gallegos
.241 -- Seth Lugo
.245 -- Roberto Osuna
.245 -- Aroldis Chapman
.249 -- Brandon Workman
.250 -- Will Smith
.252 -- Taylor Rogers

Well, this isn't it. This is mostly just a list of great relievers, who continue to be great when they have to face three or more batters. Maybe those guys are even more valuable now, but this doesn't change the calculus very much. (Except, however, that we might want to pay more attention to the relatively unheralded J.B. Wendelken, who posted a 2.55 ERA for the A's over the last two years.)

We'll have to try something else. A huge part of this, of course, is platoon splits. Righties who can get lefties out, and vice-versa, would seem to be especially useful. So let's look at that, too.

3) Righty pitchers with most relief success against lefty batters
2018-'19, minimum 40 total relief appearances

.185 -- J.B. Wendelken
.201 -- Ryan Pressly
.218 -- Seth Lugo
.224 -- Tyler Clippard
.227 -- Alex Colomé
.243 -- Jimmy Cordero
.245 -- Roberto Osuna
.246 -- Brandon Workman
.247 -- Edwin Díaz
.248 -- Trey Wingenter

OK, J.B. We see you.

Otherwise, that ... is definitely a list of names, a scattering of stars and journeymen. Let's flip it over to the southpaws:

4) Lefty pitchers with most relief success against righty batters
2018-'19, minimum 40 total relief appearances

.243 -- Roenis Elias
.246 -- Josh Hader
.250 -- Aroldis Chapman
.257 -- Taylor Rogers
.260 -- Zack Britton
.261 -- Matt Strahm
.262 -- Oliver Perez
.268 -- José Alvarado
.269 -- Sean Newcomb

Kind of the same thing, right? Definitely some stars. Definitely also Roenis Elias, for some reason.

But what we really want are pitchers who can get righties and lefties out effectively, right? It's great that, say, lefty Tim Hill has an outstanding .229 wOBA against lefty hitters when he's gone three or more batters over the last two years, but he's been splattered by righties to the tune of a .349. He's exactly the kind of pitcher who might be hurt by the new rule, but that's not what we're trying for here.

So, let's do one more thing. We'll look for pitchers who had a maximum .275 wOBA (which is very good, as the 2019 Major League average was .320) against both lefty hitters and righty hitters. They're not sorted by anything more than alphabetical. This is just the list.

5) Relievers with wOBA below .275 against both lefties and righties
2018-'19, minimum 40 total relief appearances

Anthony Bass
Aroldis Chapman
Blake Treinen
Brandon Workman
Dellin Betances
Diego Castillo
Giovanny Gallegos
J.B. Wendelken
José Alvarado
Josh Hader
Junior Guerra
Kirby Yates
Oliver Pérez
Roberto Osuna
Seth Lugo
Taylor Cole
Taylor Rogers
Trevor May
Yusmeiro Petit
Zack Britton

Now, it seems, maybe we're talking, because this is an interesting list. Right? There are the obvious studs, like Hader, Yates, Chapman, Rogers, Britton, and Lugo. There's a pair of dominating Rays in Castillo and Alvarado, and Petit, who has made a career of being a swingman who can get hitters out from both sides over multiple innings. There's Gallegos, who was already one of the best relievers you don't know.

There's Wendelken again -- maybe he's our answer -- and an interesting newcomer in Bass, who threw a career-high 95.3 mph last year, and is expected to be an integral part of the Blue Jays bullpen this year.

And yes, after all that ... there's Pérez, who didn't seem so concerned about this in the first place. His appearance here is partially because in 2018, in 55 plate appearances against righties, he allowed a mere .104/.218/.104 line against, numbers he hasn't approached before or since. In 2019 and '17, he was worse against righties. In 2016, he was about the same against both. In 2015, he was worse against righties again, but in 2014, he was far better against them.

That's part of the peril with small-sample platoon splits, of course, and ideally Cleveland isn't using Pérez regularly against a run of righties -- it's not like lefty hitters won't exist. But if you had to pick one player who might have been in danger of losing their spot, it might have been him. He's not worried, as he told Bell. If he gets the chance to face righties, he might just be able to back that up.