Historically, leadoff hitters don’t possess much power. Historically, they have served as table-setters, players who get on base so that more powerful hitters down the lineup can drive them in. Historically, all that’s true.

A look at this year’s home-run leaderboards, however, reveals Mookie Betts, Matt Carpenter, and Francisco Lindor all among the top 15. Betts is having a year that rivals Rickey Henderson’s 1990 campaign as the greatest leadoff season of all time, and Carpenter leads the National League in homers and WAR. Lindor, meanwhile, is just a lone dinger away from his second straight 30-homer season. That all bat leadoff for their respective clubs.

Because it receives the most plate appearances, the leadoff spot is, by definition, relevant to a club’s run-scoring efforts. Despite its importance, teams have generally failed to place one of their best hitters in that position. In 2002, leadoff hitters put up a 93 wRC+ overall, behind the marks posted by Nos. 3 through 6 in the lineup and virtually even with second and seventh. That’s just one year, but it’s representative of teams’ reluctance to place their best, or even second-best, hitters in the leadoff spot. The graph below shows a five-year rolling OPS+ for the leadoff spot, with data from Baseball-Reference.

For the most part, leadoff hitters have been roughly league-average hitters. They were a bit better than that in the late 1960s, when pitchers dominated everyone, and they had a great run in the late 80s and early 90s, too, when Hall of Famers Rickey Henderson and Paul Molitor were putting up great seasons at the top of the lineup. It’s possible teams spent the rest of 90s and early 2000s looking for Rickeys and Raineses and that, when they couldn’t find speedsters who got on base a ton and hit for extra bases, they merely settled on players who possessed the first of those traits. The result was suboptimal lineups that left runs on the table by giving too many plate appearances to players who weren’t among the best hitters on the team.

There’s been a noticeable change over the last decade, though, leadoff hitters have been above-average hitters for the most part. Below we see all players with at least 250 leadoff plate appearances this season.

There are still some disappointments down towards the bottom of that table, but nearly two-thirds of baseball teams are employing at least average hitters at leadoff this season. The Cubs, Giants, and Pirates, Rays haven’t landed on a leadoff hitter this season, though the Cubs’ experiment with Anthony Rizzo says they are willing to try one of their best hitters at the spot. The same is true for Brian Dozier in Minnesota even if the results weren’t there. That there are four hitters with a wRC+ of at least 140 is pretty remarkable. The table below contains all seasons since 2002 in which a hitter recorded at least 500 leadoff plate appearances and a batting line at least 40% better than average.

In the 16 seasons prior to this one, only 11 players met the criteria above. With the current season approaching its final month, there are still four hitters who meet those criteria for 2018. The top two marks on the list have been produced by players this season: Betts and Carpenter are in a position to surpass Mike Trout at something, which is always a big accomplishment. Betts is actually in the middle of potentially the greatest leadoff season of all time. A few years ago, I wrote about Matt Carpenter’s hot start and discussed the top leadoff seasons ever. Only eight times has a leadoff hitter amassed a qualifying number of plate appearances at that position and had a wRC+ at least 50% better than league average. Rickey Henderson authored three such seasons seasons. Here are the rest with their full-season totals — i.e. with PA from other spots in the lineup.

Best Leadoff Seasons Ever Player Year wRC+ BsR OFF Mookie Betts 2018 192 5.5 56.6 Rickey Henderson 1990 190 8.8 69.4 Mike Trout 2012 167 14.1 64.2 Matt Carpenter 2018 159 -0.2 35.8 Rickey Henderson 1985 159 11.7 58.3 Pete Rose 1969 154 -2.0 42.7 Rickey Henderson 1993 151 7.5 46 Don Buford 1971 151 0.6 31.6 Jacoby Ellsbury 2011 150 5.1 47.5 Shin-Soo Choo 2013 150 2.6 42.8

The projections have Betts producing a 180 wRC+ and about 67 offensive runs this year, which would both fall just short of Rickey Henderson, whose runs total likely sells him short as BsR did not contain runs on double plays or any other runs on the bases aside from steals. Carpenter is currently projected to end up with a 154 wRC+, even with Pete Rose’s 1969 season.

As for the evolution of the leadoff hitter, it has received considerably less attention than that of the No. 2 hitter. There’s good reason for that — namely, that No. 2 hitters have gotten much better over the last decade. The graph below shows the splits from every lineup position by year since the 2002 season.

A decade ago, the No. 2 spot in the lineup produced runs at a rate close to leadoff and the sixth spot in the lineup, a little bit ahead of the seven hole. As a greater understanding has emerged regarding the potential runs gained by optimizing the lineup — particularly from The Book — the No. 2 spot in the lineup has seen steady growth to the point where it is nearly even with the cleanup spot. The leadoff spot has seen growth by distancing itself from seventh, bypassing sixth, and coming even with fifth, but it really should be higher than that. The value of a home run is slightly reduced at the leadoff spot, but that doesn’t justify putting a hitter not in a team’s top three at that spot just because they hit homers.

The gains from the second spot in the lineup seem to have come at the expense of the fourth spot in the lineup. While it might garner admiration in sabermetric circles — including from myself — to bat a better hitter second, if that hitter is simply moving from the fourth spot, there isn’t a great advantage gained. The authors of The Book found, regarding lineup construction, that it is to bat the best hitters first, second, and fourth, while switching the second and fourth hitters makes little difference.

Switching the numbers for the leadoff and third hitter above might only amount to one run over the course of the season, but given that the gains in the No. 2 spot have come at the expense of the four hole with the third spot remaining on top, it’s fair to argue whether the discourse regarding lineup optimization has made much actual impact.

I should note that the extent of the impact it could make is probably limited. The question of lineup construction is mostly moot, so long as better hitters are jumbled near the top of the lineup. Nevertheless, it’s interesting to examine the achievements of this year’s leadoff hitters in context. The offenses of the Cardinals, Indians, and Red Sox have certainly benefited. It’s a great year for leadoff hitters, and more teams should consider starting their lineup with a bang.