For years, we've known that J.T. Realmuto is the fastest draw in the game behind the plate. Now, we have a new way to measure just how much of a difference-maker he is.

Statcast just introduced a brand new metric for catcher throwing: Caught Stealing Above Average. And when it comes to preventing stolen bases, there is J.T. Realmuto, and then there is everybody else.

You can watch him in action behind the plate Friday night, when the Phillies face the Astros on Apple TV+. You'll see how hard it is to take a base against him.

"It's an exciting part of the game," Realmuto said. "I enjoy when a basestealer gets on base -- I obviously don't want anyone on base, to be clear -- but I enjoy that part of the game. So it excites me when there's a basestealer out there and I have a chance to throw him out."

Here are the catchers at the top of the Caught Stealing Above Average leaderboard for all years combined (the stat goes back to 2016):

"He can control the run game by himself," said Phillies shortstop Trea Turner, who has a unique perspective on Realmuto as one of the game's best basestealers, who used to have to run against Realmuto and now is putting tags down for him.

"J.T. and Yadi are the two guys that come to mind."

Here's what Realmuto's CSAA number means, and why it matters.

Caught Stealing Above Average is the first catcher stat of its kind, because it isolates the catcher's skill at controlling the run game. The baseball wisdom goes: "You steal off the pitcher, not the catcher," and that is largely true. Pitchers have a huge influence over stolen bases, through holding runners on and how fast they are to the plate. CSAA takes the pitcher out of the equation, looking at how likely the catcher is to catch a basestealer at the time the pitch crosses the plate -- based on the runner's lead, his speed, the pitch type and location and the pitcher's and batter's handedness.

And there, Realmuto dominates the catcher position. He is the great equalizer in this new era of pickoff limits and the pitch timer, when it's harder for a pitcher to prevent stolen bases than ever before.

"I think catchers' value goes up a lot," Turner said. "Guys like J.T. still throw runners out and control the run game."

"I've always taken pride in getting the ball to second base fast, so I'm going to continue to try my best to do that," Realmuto said. "You can't put any extra pressure on yourself, because I can't try to do any more than I'm already doing. I'm going to give up some more stolen bases, that's just part of it."

If there's anyone who's up to the challenge of keeping the run game in check in 2023, it's Realmuto. Because what he's "already doing" is outclassing basestealers, and his catching peers, year in and year out.

Not only does Realmuto have the best Caught Stealing Above Average total of the Statcast era by far, he also has the best individual seasons by far -- and he's coming off one of those seasons in 2022. (This year, he's at +2 CSAA, right behind the league leaders.)

Let's watch Realmuto in action. Here are three of his top caught stealings by CSAA since the start of last season -- his best so far in 2023, and his two best of 2022.

1) April 2, 2023 vs. Marcus Semien

Realmuto's CS probability: 15%

How he did it: With a ridiculous 1.76 second pop time -- the fastest on any caught stealing in MLB this year. Even Semien's excellent 28.7 ft/sec sprint speed wasn't enough to save him.

2) Sept. 6, 2022 vs. Luke Williams

Realmuto's CS probability: 7%

How he did it: Quick release. Realmuto's exchange took just 0.59 seconds, producing a 1.74 second pop time that was second best on any caught stealing at second last season. (He also had No. 1.) He bounced this throw, but it got there so fast that it gave shortstop Edmundo Sosa a chance, and he came through with the pick and tag in one motion.

3) June 24, 2022 vs. José Azocar

Realmuto's CS probability: 7%

How he did it: With his strongest throw of the year on a caught stealing, 87.9 mph. Azocar is one of MLB's fastest runners, and he had a borderline-elite 29.7 ft/sec sprint speed. But Realmuto's throw got to second base on the fly in 1.77 seconds, and Johan Camargo slapped down a quick tag.

Those three caught stealings are perfect examples of what makes Realmuto so great: He just gets the ball to second base faster than anyone else.

That sounds obvious -- we already know Realmuto owns Statcast's pop time leaderboard. He's led MLB in pop time six seasons in a row -- and in 2022, he had 14 of the 15 fastest caught stealings at second base.

Realmuto's avg. pop time to 2B by season
2016: 1.91 seconds (T-2nd in MLB)
2017: 1.90 seconds (2nd in MLB)
2018: 1.90 seconds (1st in MLB)
2019: 1.88 seconds (1st in MLB)
2020: 1.83 seconds (1st in MLB)
2021: 1.83 seconds (1st in MLB)
2022: 1.82 seconds (1st in MLB)
2023: 1.82 seconds (1st in MLB)
MLB average: 2.00 seconds

"The catcher position's gotten so much more athletic in the last 5-10 years, and he's part of that," Turner said. "When the game gets better and he's still at the top of it, it speaks to how consistent he is … That's where he separates himself."

But what we can measure for the first time is exactly how much of a difference those pop times make for Realmuto throwing out each runner.

Caught Stealing Above Average breaks down catchers throwing out basestealers into each of its individual components: arm strength, release time, accuracy and teamwork, which basically covers the infielder tagging the runner. And what we see is the tradeoff between speed and accuracy.

"I have really good infielders who I trust to get the tag down," Realmuto said. "So that helps me a lot, where I can feel like I can get it down there as fast as I can because I trust those guys to catch it and finish the play."

A catcher could take extra time to try to make a perfect, pinpoint throw. Realmuto does not. His No. 1 priority is: Get the throw down ASAP, and he leaves it to his infielders to make the tag.

"It's a lot better [being on his side] -- I don't have to worry about getting thrown out," Turner said. "He just gets rid of it so quick. The one thing I've noticed since I've been here is, he takes a lot of pride in it. He works on it; we work on it from a tagging standpoint. The pride in getting those extra outs is a big deal over here."

Realmuto's CSAA breakdown is a beautiful illustration of his approach. Where he stands out from other catchers is his throwing speed and quick release -- even at the cost of perfect accuracy -- and his reliance on teamwork to complete the caught stealing, whether his throw is on the fly or bounced.

Realmuto's CSAA breakdown, all years
Throw speed: +28
Exchange: +13
Teamwork (bounced throws): +10
Teamwork (on-the-fly throws): +4
Accuracy: -10

Last season, when Realmuto's +15 CSAA was 10 caught stealings better than the second-best catcher (Martín Maldonado), he got +13 CSAA from arm strength and release speed, +3 CSAA from teamwork … and -1 CSAA from accuracy.

In other words: Realmuto is so fast to second base that it doesn't matter if the throw is perfect. It might even be better that it's not, so Realmuto doesn't sacrifice the elite pop times that are critical to throwing out elite speedsters.

In fact, Realmuto will often bounce a throw on purpose, because aiming low lets him get the ball out a fraction of a second faster, which can make all the difference when the league's top basestealers are running against him … or, trying to.

"I try to bounce it quite a bit, actually," Realmuto said. "If I see a guy get a huge jump, sometimes it's quicker to get the ball out and get it low as opposed to trying to make the perfect throw every time in the air. I can get it out a little faster if I trust the bounce and trust the long hop."

Realmuto nails runners regardless of their jump or their speed. He's caught runners stealing second on 39% of his total throwing opportunities going back to 2016, while his estimated caught stealing percentage over that time, according to Statcast, is just 25%. That's how often a typical MLB catcher would throw out the baserunner.

These are the best catchers in the world we're talking about. But Realmuto is just the best of the best catchers in the world.

The basestealers know it. Just ask Turner. He remembers when he was on the other side.

"A lot of times, maybe over 90% of the time, you're stealing off the pitcher. The catchers don't matter too much," Turner said. "But there are those fringe ones where you're like, 'Man, I've gotta be perfect here, or else he's gonna get me.' I've definitely thought about it. Just that thought, that J.T. puts in other guys' heads, is a win for him and his team."

Paul Casella contributed reporting to this story.