NEW YORK — They own the majors’ best record since the All-Star break, but the 2019 Mets remain a work in progress. Winners of 27 out of 40 games in the second half, they’ve played themselves back into contention for a postseason berth, and energized Citi Field, but after winning 10 out of their previous 12 series, they spent this past weekend making mistakes, missing opportunities, and ultimately dropping their second series in as many weeks to the Braves — this time via a three-game sweep at home.

In Friday night’s 2-1 loss, the Mets squandered a seven-inning, 13-strikeout gem by Jacob deGrom, who provided the team’s only run of the night on a solo homer, his second of the year. For as well as the reigning NL Cy Young winner pitched, opposite number Mike Foltynewicz — who entered the evening with a 6.09 ERA and a 5.82 FIP, numbers more than double those deGrom — yielded just one other hit besides the homer over his seven innings. The 1-1 tie carried into extra innings, and after the scuffling Edwin Díaz stranded pinch-runner deluxe Billy Hamilton at third base by striking out both Ronald Acuña Jr. and Ozzie Albies in the top of the 10th, the Mets got the winning run to third in the bottom of both the 10th and 11th themselves, but failed to convert; the team went 0-for-7 with runners in scoring position on the night. Ultimately, a 14th-inning single by Hamilton (who entered hitting .211/.275/.269) off Jeurys Familia brought home the deciding run.

In Saturday night’s 9-5 loss, Zack Wheeler was knocked around for his third straight start, putting the Mets into a 4-0 hole by the middle of the third inning. They clawed their way back, and took a 5-4 lead when Pete Alonso walloped a 451-foot three-run homer into the black batters’ eye, tying the franchise’s single-season home run record — 41, previously reached by Todd Hundley (1996) and Carlos Beltran (2006) — and reaching 100 RBI in one fell swoop. Two significant defensive mistakes, an error by third baseman Todd Frazier on a grounder down the line by Francisco Cervelli in the sixth inning, and a lackadaisical relay play by left fielder J.D. Davis in the eighth, both led to runs, while a baserunning out at third base by Jeff McNeil, that after a pair of bunt attempts by hot-hitting Amed Rosario, snuffed a potential sixth-inning rally.

In Sunday’s 2-1 loss, the Mets could do little against Braves starter Dallas Keuchel, who shut them out for seven innings while allowing just four hits, all singles. Steven Matz answered with six innings of two-hit ball, but one of those hits was a Josh Donaldson homer, and the Braves’ third baseman greeted reliever Paul Sewald with another one in the seventh inning. The Mets broke through in the ninth inning against Mark Melancon, albeit on a fielder’s choice off the bat of Frazier that nearly became the team’s fourth double play of the afternoon. Ultimately, the tying run was stranded at second base, the last failure in a 1-for-8 day with runners in scoring position. So it goes.

When the Mets raised eyebrows around the league by acquiring Marcus Stroman from the Blue Jays on July 28, they were 50-55, 11 1/2 games out of first place in the NL East and six back in the Wild Card race. They were starting to show signs of life, having won nine of their previous 13 games at that point, but with playoff odds of just 11.2% (10.5% for the Wild Card), it seemed a stretch to consider them contenders. No more. They entered this series having gone 17-5 since the trade, and since the All-Star break had lost series only to the Giants (three out of four from July 18-21 in San Francisco) and Braves (two out of three in Atlanta from August 13-15).

Driving the Mets’ second-half surge has been a rotation that, in the days and weeks before the July 31 deadline, appeared as though it might be on the chopping block, with general manager Brodie Van Wagenen fielding offers on both Noah Syndergaard (who has two more years of club control remaining) and Wheeler (who will hit free agency this winter), with Stroman’s arrival perhaps designed to take the sting out of such moves. Instead, the unit remained intact, and it has enjoyed an elite run, posting the lowest ERA and FIP in the entire majors (2.71 and 3.11, respectively) in that span while allowing a major league-low 0.71 homers per nine as well. Their 7.2 WAR is 1.5 ahead of the majors’ second-best rotation in that timeframe.

Mets Rotation Since the All-Star Break Pitcher GS IP ERA FIP WAR Noah Syndergaard 8 54.1 1.82 2.15 2.2 Jacob deGrom 8 52.0 1.04 1.68 2.5 Steven Matz 8 47.2 2.64 3.02 1.4 Zack Wheeler 6 36.1 3.72 3.88 0.7 Jason Vargas* 4 22.2 4.76 5.69 0.1 Marcus Stroman** 4 19.2 4.58 4.89 0.2 Walker Lockett 2 9.2 4.66 4.04 0.1 * = traded to Phillies on July 31. ** = acquired from Blue Jays on July 28.

DeGrom, the reigning NL Cy Young winner, has pitched his way back into the awards conversation, particularly with Max Scherzer making just two starts since July 6 due to back woes, and Hyun-Jin Ryu getting pounded twice to balloon his ERA to 2.00 (gasp). DeGrom’s 2.56 ERA is fourth in the league and his 2.68 FIP second. He’s now tied for first with Scherzer in WAR (5.6) and overtook him in for the lead in strikeouts; Friday’s baker’s dozen took him to 207, making him the first NL pitcher to reach 200 this year (five pitchers have done so in the AL).

Syndergaard hasn’t been quite as stifling, but he’s turned his season around after a mediocre first half (4.68 ERA, 3.99 FIP) to rank eighth in the NL in FIP (3.36) and tie for fifth in WAR (4.0). Matz has turned the page on an ugly first half (4.89 ERA, 5.40 FIP). Wheeler, who was sidelined by a bout of shoulder impingement just after the All-Star break, which couldn’t have helped his trade value, allowed just three runs in 20.1 innings in his first three starts upon returning, but since then has been tagged for 14 runs (12 earned) in 16 innings over his last three starts, with just seven walks and strikeouts apiece.

On Saturday night, Wheeler’s troubles began when he issued back-to-back walks to Matt Joyce and Adeiny Hechavarría to start the second inning. Cervelli, making his debut with the Braves after being released by the Pirates earlier in the week, brought both runners home with a double but was thrown out in a rundown once he strayed too far past second base. In the third inning, Wheeler served up solo homers to both Ozzie Albies and Donaldson.

“Out of the stretch, I was a little off today,” said Wheeler afterwards. “I was trying to throw more four-seams arm side and that just wasn’t there the first few innings. So I said screw it and start throwing two-seams because I knew it was going to be there.”

Wheeler chastised himself for getting first-pitch strikes against just 11 of the 28 batters he faced. “I fell behind a lot of guys and a lot of deep counts and kind of set guys up for fastballs. I just need to do a better job of getting ahead of guys, it makes it a lot easier and I’ve had my success when I do get ahead of guys.”

After allowing the four runs, he settled down to post zeroes in the fourth and fifth innings. The Mets scored one run against Braves starter Max Fried in the third inning and then four against him in the fifth, three on Alonso’s big blast, which gave them a 5-4 lead:

HISTORY! Pete Alonso has tied the #Mets record for home runs in a single season with 4?1?. pic.twitter.com/Tj8wq5NmIv — New York Mets (@Mets) August 25, 2019

“That gave me the chills a little bit with the atmosphere and the timing of the home run and how big it was,” said Wheeler, but only after noting his own failure in the top of the sixth. “I was frustrated that I didn’t get that shutdown inning after Pete had that home run.” With one out, Frazier could not backhand Cervelli’s 88.8 mph grounder down the third base line; it was ruled a two-base error, and Rafael Ortega’s subsequent RBI single knotted the game.

The Mets had a chance to take the lead when McNeil, making his return from a 10-day absence due to a left hamstring strain, laced a pinch-double off reliever Josh Tomlin to start the seventh. Up came Rosario, who since the All-Star break has hit .348/.382/.500 for a 134 wRC+, and who had gone 2-for-2 to that point in the game. The pressure was on the Braves, but manager Mickey Callaway signaled for Rosario to bunt, and suddenly one could hear the echoes of his postgame declaration from a week and a half ago: “I bet 85 percent of our decisions go against the analytics, and that is how it’s always going to be, because that is just on paper. It doesn’t take into account the person is a human being, how he performs in these big spots, all these things a manager looks at.”

Rosario tried to bunt, but his first attempt went foul. He squared around again, but drew back and took strike two, then hit a slow chopper to Hechavarría, who threw to Donaldson at third base for the out — a close play that was challenged by the Mets, unsuccessfully.

Mets challenge call that Jeff McNeil is out at 3B in the 7th; call confirmed, runner is out. Powered by @Mitel. pic.twitter.com/At22FdfDmu — MLB Replays (@MLBReplays) August 25, 2019

It was a puzzling sequence. Callaway lauded McNeil’s aggressive baserunning but praised the defense of Hechavarría, who played 60 games for the Mets before being released on August 14.

“You’re looking for a ball to the right side in that situation, but there are a few hit in front of you that you can get on, the chopper to the third baseman, where he has to come in. He knows where the shortstop is. A chopper to your right you go on, because most guys just come in and throw that underhand to first and Hech just came up and gave the no look to third. It was really a great play.”

The manager took ownership of the call to bunt, adding:

“Tie game, we wanted to get that runner over to third. The way [second baseman Joe] Panik’s been swinging the bat, and his ability to touch the ball, we figured that he would get him in, and we knew that Rosie has been doing a great job of hitting with two strikes. He’s been leading the second half in base hits with two strikes so we figured, hey, we’re covered either way. If he gets him over, we’re probably going to score that run and take the lead and then give it to our bullpen and if not, Rosie can still try and swing the bat with two strikes.”

The splits do show Rosario hitting .301/.326/.386 with 25 hits (one shy of the NL lead) when batting with two strikes since the All-Star break, but again, that’s not nearly as strong as his overall second-half performance, and his 102 wRC+ for the season dwarfs that of Panik (71 overall, and 87 as a Met). This must be what it looks like to go against analytics 85 percent of the time.

Things did not go well from there for the Mets. They didn’t score, and in the top of the eighth, reliever Brad Brach allowed a trio of two-out singles by Ortega, Hamilton, and Acuña. The last of those went to Davis in left field, who saw Hamilton blaze to third base before relaying the to Rosario, only to watch the speedster turn on the jets:

“I was going to make a play to third,” said Davis afterwards, “and then I saw that the runner [Hamilton] was already like three-quarters of the way … so I just held onto the ball, and I looked at first to see where that runner was. But then as I released it to throw it to Rosie, he was already rounding third and headed home … I should have just thrown it to Rosie and got it in. [You feel kind of] helpless, with Hamilton and his speed … it was just perfect timing. It was a good, high-baseball IQ kind of play.”

The situation only worsened, as Díaz entered in the ninth and on his fourth pitch, served up a solo homer to Freddie Freeman. He recovered to strike out Donaldson, but walked pinch-hitter Charlie Culberson and then departed with the trainer after complaining of tightness in his right trapezius muscle, an issue that he felt as he warmed up. Replacement Chris Flexen surrendered another RBI double to Cervelli (his third hit on the night) to run the lead to 9-5. Ballgame.

The bullpen and defensive follies were reminiscent of the Mets’ first half, when they finished last in the NL in defensive efficiency (.670) and UZR (-23.5) and tied for last in the majors in DRS (-67). They’re up to .678 in defensive efficiency — the team’s BABIP (essentially 1 minus def eff) has improved from .311 in the first half to .287 in the second — and to -19.1 in UZR, but Saturday night’s lapses loomed large.

Likewise for the bullpen, which entered having posted the league’s second-lowest second-half ERA (3.64), seventh-best FIP (4.64), and fifth-best WAR (0.7), that after a first half with a 5.63 ERA, 4.93 FIP, and -0.3 WAR. Díaz, who owns a 5.55 ERA and 4.61 FIP overall, has been ugly throughout the season, with glimmers of hope like Friday night’s quickly washed away. Seth Lugo has come up big, and both Familia and Justin Wilson and have pitched well since returning from injuries in early July, though Friday simply wasn’t the former’s night as he retired just three of the seven batters he faced while allowing the go-ahead run.

The sweep knocked the Mets’ playoff odds from 51.4% (50.2% for the Wild Card) to 33.2% (33.1% for the Wild Card). At 67-63, they’ve slipped into fourth in the NL East, 12 games behind the Braves (80-52), six behind the Nationals (73-57), and half a game behind the Phillies (67-62), the last of whom is now 1 1/2 games out of the second Wild Card spot to the Mets’ two games. The soft part of their schedule — six straight series against sub-.500 teams — is over; their .503 remaining strength of schedule isn’t nearly so hard as the Phillies’ (.525), but it’s harder than that of the Wild Card-leading Nationals (.492) and Cubs (.500); they play their next four series against those three teams; they’re 2-2 against the Cubs (whom they host), and 10-6 against the Nationals (whom they visit), but 4-9 against the Phillies, with whom they play home-and-home series. For as resilient as the Mets have shown themselves to be by rallying from their first-half nadir, they have more work to do if they’re going to salvage this season.