Last night, the Mets won 3-2 over the Pirates on three runs deserving the “manufactured” classification. Every run required a baserunner to take an extra base. John Buck scored on a sacrifice fly in the third inning after he went first-to-third on a single. Andrew Brown scored from first on a double in the seventh inning, and Marlon Byrd scored the game-winner on a relatively shallow single to center field by Mike Baxter.

Don’t be surprised. The Mets now lead MLB in runs added from baserunning at 5.6, just over the Red Sox at 5.4, and they’ve done it despite stealing just 13 bases, 24th in the league. How? They don’t make outs, and they take nearly every base possible when the ball is put in play.

Overall, the Mets have not hit particularly well this season. Their .233/.308/.388 line comes out to a 94 wRC+, 17th in the majors. Despite their general mediocrity, however, the Mets are eighth in the majors and third in the National League with 4.7 runs per game, 0.4 runs better than the league average.

Part of it is success with runners on: the Mets have a 114 wRC+ with runners on base, fourth in the league. But that doesn’t explain it all — the Mets have had the third-least plate appearances with runners on. Additionally, their .427 slugging percentage is ninth in the league and their 15 home runs ranks 13th.

But the Mets have been making the most of their singles and doubles, just as they did last night. They haven’t ran into outs — their six non-CS, non-pickoff and non-force outs on the bases are the second least, behind just Kansas City’s three. And they’ve been wildly successful in taking the extra base.

Fifty-one times the Mets have had a runner on first with a single, and 21 times he has reached third, a league-leading 41.2 percent extra-base rate. The Mets have had a runner on first on 16 doubles, and nine times he has scored, a third-place 56.3 percent extra-base rate. And 32 times the Mets have had a runner on second for a single, and 24 times he has scored, a second-place 75 percent extra-base rate (all data from Baseball-Reference).

Between the three categories, the Mets have advanced 14.5 more bases than expected. The next closest team is the Cubs, at 9.9. The Mets haven’t been a great hitting team, and they don’t project to be one for the rest of the season. But they’ll keep scoring over their heads if they can maintain this aggressive baserunning.

Whether or not their pitchers can make those runs stand up is another story, but at 14-17, the Mets have somewhat outplayed expectations over the first month and a half. Give credit to the Mets baserunners and the coaching staff — they’re making every baserunner count, a necessity given the lack of oomph in the Mets’ lineup this season.