It has been only three weeks, but Major League Baseball’s ABS challenge system has ushered in a whole new genre of statistics in a sport that was already known for the treasure trove of numbers and data points that help us understand what’s happening on the field. With players now having the option to challenge umpires’ strike-zone judgment — but with just two challenges per game and only successful challenges retained — we have a fascinating, new way to compare teams’ successes, failures and tendencies.We’re still in the earliest stages of comprehending how the ABS challenge system is best utilized — and so are the teams.

Even so, it hasn’t taken long for some intriguing trends to emerge, so here are a few takeaways from what we’ve seen so far.Which teams have been the best and worst at using the ABS challenge system?Through three weeks of MLB play, there have been 1,143 challenges issued. Of those, 619 have been successful, meaning players have been right more often than not when challenging an umpire’s ball or strike call, with a 54% overturn rate. But not all teams are succeeding at this clip.

Some have been much better, and some have been much worse: Nine clubs have a success rate above 60%, with the Reds comfortably ahead of the pack at a whopping 72%, while three teams — the Braves (39%), Guardians (39%) and Nationals (34%) — fall below 40%.There’s also a pretty wide range in how often teams are challenging. Cincinnati’s league-best mark comes with only 29 challenges, tied with Washington for third-fewest of any team. Meanwhile, the Twins are tapping their heads all the time, having already challenged 61 calls this season — nine more than the second team, Colorado at 52 — with a 57% overturn rate.

This makes basic sense; teams retain challenges if they are correct, and thus can rack up a larger raw total by overturning more calls. On the flip side, it’s been harder for teams such as Washington to challenge more frequently when the Nats have so often been incorrect early in games, thus running out of opportunities to protest calls.When during games are challenges happening the most?Before we look at some more team-specific trends, here’s an overview of the game situations in which challenges have been utilized most. Entering the season, it stood to reason that teams would try to save challenges for higher-leverage moments later in games, but so far, that hasn’t really been the case.

Here’s a breakdown of challenges by inning:1st inning: 1112nd inning: 1013rd inning: 1114th inning: 1035th inning: 1186th inning: 1387th inning: 1598th inning: 1489th inning: 138Extras: 16Among this sample, there is a slight lean toward the later frames, but so far — whether or not teams are explicitly green-lighting this behavior — players have been happily tapping their heads early in games.Which hitters have yet to challenge?So far this season, 252 batters have challenged at least one called strike. But there are some holdouts who haven’t tried MLB’s new toy, for whatever reason. Here are the hitters who have seen the most called strikes without issuing a single challenge:1.

Chase Meidroth: 77 strikes2. Brice Turang: 683. José Ramírez: 634. Masyn Winn: 605.

Mike Yastrzemski: 58T-6. Matt McLain: 57T-6. TJ Friedl: 57T-6. Jung Hoo Lee: 579.

Will Smith: 56T-10. Francisco Lindor: 54T-10. Drake Baldwin: 54This is not to say these players saw many horrific calls by the umpires that deserved to be protested.

And perhaps there have been times when they would’ve liked to challenge, but their teams didn’t have any left. At the same time, it’s not hard to watch some of the called strikes for these hitters and wonder: What are you waiting for?!Still, we can be patient as hitters around the league settle into the new system. And having two catchers on this leaderboard makes sense; Smith and Baldwin would probably rather save their challenges for when they’re behind the dish.

As for the rest of this group, it’ll be interesting to track how long some of these guys go without challenging and whether this is merely early-season hesitation or a conscious choice to neglect their new privilege.Are teams preferring to challenge more while batting or while pitching?Of the challenges issued, 611 (53%) have been by the fielding team (with the vast majority of those issued by catchers) and 532 (47%) by the batting team. But certain teams have demonstrated more significant splits. Here’s a breakdown of which teams’ challenges have leaned most heavily toward one side of the ball:Highest percentage of challenges on defense:Dodgers: 73% (24 of 33 challenges issued while pitching)White Sox: 72% (31 of 43)Marlins: 71% (35 of 49)D-backs: 66% (21 of 32)Brewers: 65% (28 of 43)Highest percentage of challenges on offense:Tigers: 64% (25 of 39 challenges issued while batting)Yankees: 63% (29 of 46)Orioles: 59% (22 of 37)Guardians: 58% (21 of 36)Blue Jays: 57% (21 of 37)This is one indicator of teams’ strategic preferences that’ll be worth monitoring as the