Charlie Blackmon’s RBI onslaught started in the seventh inning of the Rockies-Brewers game on Opening Day. With one out and the bases loaded, the Rockies center fielder drilled what looked like a double-play grounder to Orlando Arcia at short. Arcia flipped it to Jonathan Villar for the second out, but Villar bobbled the ball on the transfer and couldn’t complete the turn. Mark Reynolds scored from third, and Blackmon was safe at first, awarded with his first RBI of the season. Since then, he’s added 45 more.

The RBI’s battle for analytical value is long since decided: The run batted in, for decades a prominent method of player evaluation, has become a statistical curiosity prized by only players, salary arbitrators, fantasy owners, and fans who haven’t moved on from old-school stats. Nowadays, we take notice only when a player has an extraordinary number of RBIs, on either the high or the low end. Last year, Orioles backup catcher Caleb Joseph briefly became a player people had heard of when he set a single-season record for at-bats and plate appearances without an RBI. (He finally got back on the board with a two-run homer on April 29 of this season.) And through the first two months of this season, Blackmon is pursuing his own freak RBI accomplishment, albeit one without the stigma of Joseph’s streak.

Blackmon, who’s hitting .329/.364/.625 with 13 home runs and an MLB-high eight triples, is also leading the big leagues with 46 RBIs. That puts him on pace for 138, which would be the most any hitter has had since 2013. But that’s not the strange part. The strange part is that Blackmon bats leadoff.

The primary reason the RBI has lost its privileged position is its failure to consider context: It makes no adjustment for where a player hits in the lineup or who hits ahead of him, two factors that significantly skew hitters’ totals. That context is also what makes Blackmon’s start so surprising. Because leadoff hitters are guaranteed at least one plate appearance per game with no runners on — and because they come up after low-OBP players thereafter, particularly in the NL, where the pitcher hits eighth or ninth — it’s harder for them to drive in runs than it is for anyone else. The graph below shows the average number of runners on each base when NL hitters have come to the plate over the past seven-plus seasons, broken down by batting-order position.

On average, NL leadoff hitters have had 0.43 runners on base when their plate appearance started. Hitters in non-leadoff lineup slots have averaged 0.62 runners on base, led by cleanup hitters with 0.68. Admittedly, leadoff hitters make more plate appearances, period — Blackmon is tied for the major league lead — but that huge runners-on disadvantage explains why we almost never see leadoff hitters touch triple-digit RBI totals, let alone lead the league. Since 1974, when FanGraphs’ splits by batting order begin, only Darin Erstad has driven in 100 runs in a season while batting leadoff, and only 11 leadoff hitters have come within 50 runs of the major league RBI lead.

Faced with those obstacles, Blackmon — a very good player, but not quite an elite one — has benefited from a confluence of circumstances that have helped him pull off the improbable through the first third of the season.

The Coors Effect

Whenever a Rockies hitter does something special, the reflexive response is “Coors Field.” It’s not an unfair explanation: Coors remains by far the most inflated offensive environment in baseball, increasing scoring by 18 percent relative to the league average. More runs, quite clearly, means more runs batted in. It’s no coincidence that the Rockies’ Nolan Arenado led the majors in RBIs in each of the past two seasons.

That said, Blackmon’s RBI run is extreme even by Rockies standards. He already owns the franchise record for RBIs by a leadoff batter, which he set last season, when he tied the Tigers’ Ian Kinsler for the major league lead with 82. At the pace he’s played at thus far, he would blow by that mark with months left to go.

Moreover, the Rockies’ offense isn’t so strong: After park adjustments, it ranked 27th in production per plate appearance entering play Tuesday. Granted, the team trailed only the Nationals in runs scored (thanks, Coors), but the lineup is top-heavy: Blackmon has been the Rockies’ best hitter, and the bottom of the lineup — the hitters who bat before Blackmon when he’s not leading off the game — doesn’t stand out. Even with the Coors effect, the Rockies’ on-base percentages out of the seventh, eighth, and ninth slots were only six points better, three points worse, and 19 points worse, respectively, than the NL average for those lineup positions when Tuesday’s games began.

The Leadoff Revolution

As my colleague Zach Kram chronicled in March, teams are getting a little more liberal in their understanding of what constitutes a leadoff hitter. No longer is the leadoff slot limited to speedy, high-average hitters who steal bases; power hitters are welcome, too. Last year, Blackmon launched 29 homers and saw his stolen-base total fall from 43 to 17. In an earlier era, that might have gotten him bumped down in the lineup to a more traditional slugging slot. Today, he gets to stay, enabling his anomalous start to the season.

The leadoff revolution has hit some snags so far: After setting some all-time offensive highs last season, leadoff hitters have been well below league average at the plate in 2017. (The Cubs’ Kyle Schwarber, the poster boy for the leadoff slot’s evolving appearance and performance, has hit only .173 with modest power.) However, as measured by isolated power (SLG-AVG), they’ve still posted their second-best power performance relative to the league since at least 2001, trailing only last season. The leadoff spot is still a safer harbor for home run hitters (and, by extension, Blackmon) than it’s tended to be in the past.

Fortuitous Timing

This is the big one. With the exception of a likely line-drive out in April that Hunter Pence misplayed into an inside-the-park homer, Blackmon hasn’t been “lucky” in the way we usually mean when we talk about batters: His BABIP and home-run-per-fly-ball rate are high by leaguewide standards, but less high by Coors standards and barely above Blackmon’s full-season figures from 2016.

Blackmon has, however, been extremely lucky in how he’s timed his hits. Before this season started, Blackmon had been a better career hitter with the bases empty (110 wRC+, where 100 is average) than with runners in scoring position (104 wRC+) or with men on base (96 wRC+). This year, though, he’s done the bulk of his damage at the most opportune times, pairing (through Monday) a decent 116 wRC+ with the bases empty with a spectacular 181 wRC+ with men on and a major-league-leading 243 wRC+ with runners in scoring position. With someone(s) on second and/or third, no qualified hitter has been better than Blackmon.

Due to his lineup position and the Rockies’ lackluster bottom of the order, Blackmon hasn’t had that many RBI opportunities. Despite his high RBI count, Blackmon entered Tuesday in a three-way tie for 90th place in the number of runners on base when his plate appearances started. (The Reds’ Adam Duvall, who trails Blackmon by one RBI, ranked third on the list with 41 extra runners.) Yet Blackmon has made the most of those opportunities, converting runners into runs at a major-league-leading — and yes, unsustainable — rate. Blackmon has plated 28.4 percent of the runners on base at the beginning of his plate appearances. Even setting a low minimum of 230 plate appearances (Blackmon has 239), that would be the highest seasonal rate in the past 60-plus years, topping a list that features a few pre-humidor Rockies.

Even if Blackmon hadn’t bunched his hits at big moments, he would be worthy of the All-Star start the fans seem set to deliver. Because he has, though, he’s vaulted himself to the top of a leaderboard that’s hostile to leadoff hitters and has helped propel the Rockies’ cluster-luck-aided offense to a 33–21 record, one game in the NL West loss column behind the heavily favored Dodgers. This kind of craziness can’t keep up, but it’s already lasted long enough to make the RBI relevant, if only for one man and one moment.

Thanks to Rob McQuown of Baseball Prospectus and Jeff Zimmerman of FanGraphs for research assistance.