OAKLAND — You only have to go back a few weeks — to June 15 — to find a time where it was realistic to think that that the A’s were going nothing more than to be a mediocre team in 2018.

That was the night the A’s fell behind 8-0 to the Angels, en route to an 8-4 loss, and sophomore third baseman Matt Chapman went on the disabled list with a wrist injury.

Manager Bob Melvin lamented after the contest that his team was playing its worst ball— the loss was their 12th in their last 13 contests against American League West foes, and it dropped their record to a fourth-place 34-36, 11 games back of a Wild Card spot.

But from that nadir forward, the A’s have played their best baseball. They came out of that loss to the Angels with a five-game winning streak that, following a three-game sweep of the Blue Jays on Wednesday, has morphed into a 30-10 run — the best record in baseball since mid-June — and ownership of the second Wild Card in the American League.

The A’s mid-season explosion has been inspiring, engrossing, and downright unpredictable, but what’s been most intriguing about this run has been the fact that Oakland’s starting pitching rotation is effectively duct taped together.

One would presume that strong starting pitching would be a critical aspect of any successful run towards the playoffs, but the A’s are bucking that trend — only twice since that turning-point game in mid-June has Oakland seen a starter make it through the seventh inning.

Instead, the A’s are pushing towards playoffs through clutch power hitting, a dominant back-end of the bullpen that only became stronger in recent weeks, and something larger that’s impossible to quantify but impossible to ignore.

This isn’t Moneyball 2.0 — these A’s aren’t revolutionizing the game — but this team is showing that its the epitome of baseball’s Statcast Era.

Or, to put it another way: the A’s are baseball’s most 2018 team.

And that portends well for Oakland over the last two months of the regular season and — should they advance — in October, too.

Since Sean Manaea went seven innings in a win over the Padres on Independence Day, the A’s have gone 23 games without a starter reaching the seventh inning. It’s not surprising that Manaea is the man who has gone deep for the A’s — he’s the only pitcher in the A’s current rotation that was expected to be in it at the beginning of the season.

The A’s went into Spring Training with the makings of a solid young rotation, but before camp broke, Jharel Cotton required Tommy John surgery and Paul Blackburn was dealing with forearm tightness.

Still, the A’s had a rotation of Kendall Graveman, Manaea, Daniel Gossett, Daniel Mengden, and Andrew Triggs. Big talent and upside with that five-man unit.

But of that group, only Manaea and Mengden are healthy at the moment, and the latter is in Triple-A.

Graveman, who was the A’s Opening Day starter but was sent down after a month of play, underwent Tommy John surgery in June. Gossett left an early June start with forearm tightness that brought about Tommy John surgery this week. Triggs was shut down in May with a nerve issue in his throwing hand — after a setback in recovery, he just resumed throwing this week.

Down seven major league starters — seven — and a few more minor league prospects who might have been able to slide into big league jobs (A.J. Puk, Grant Holmes) the A’s have opted to turn to old, familiar faces who are willing to work on the cheap to start games.

The A’s signed Brett Anderson to a minor league contract in March — he’s made eight starts and posted a 5.55 ERA — and Trevor Cahill to a one-year, $1.5 million deal — he’s started 12 games and posted a 3.39 ERA.

And rounding out what is effectively a four-man rotation (Frankie Montas is called up from Triple-A when the A’s need a fifth starter) is Edwin Jackson — he of 13 teams in 16 major league seasons. Jackson, who was signed to a minor league deal in June, has posted a 3.32 ERA in seven starts for the A’s.

So far this season, A’s starters have posted a 4.34 ERA and the second-worst strikeout rate in baseball — downright unremarkable numbers unbecoming of a playoff team — but the team keeps winning.

That’s because for the A’s, starting pitching is just a necessary conduit to the team’s bullpen.

A’s relievers have posted a guady Win Probability Added of 9.16 this season, far and away the top mark in the big leagues. With closer Blake Treinen, who, per that WPA metric, is the best reliever in baseball, rookie flamethrower Lou Trivino (2.87 WPA), and now former Mets closer Jeurys Familia, who was acquired via trade in June, the A’s have as formidable a 7th-8th-9th-inning combination as any team in baseball.

Bullpens have always been important in baseball, but in this era of starters throwing fewer innings than ever, they’ve become particularly critical to both regular season and playoff success in recent years — just look at the 2015 Royals, the 2016 Indians and Cubs, and last year’s Dodgers.

If Treinen, Trivino, and Familia can keep up their current pace, they can make the A’s bullpen stack up with any of those aforementioned teams. Good company to keep.

In essence, with those three, the game is six innings long for opposing hitters (and the A’s other pitchers), while Oakland’s bats get to go the full nine.

That’s a huge advantage for Oakland, because the A’s offense is downright dominant in late-inning situations.

In innings one through six, the A’s have posted a .711 OPS this season — 24th in baseball.

But from the seventh inning on? Look out.

Oakland has scored 211 runs in the seventh inning or later this year — the top mark in baseball and 20 runs more than the next-best American League team, the Astros. The margin is even more comical when you only look at the eighth inning or later, where the A’s have scored 153 runs (nearly 20 percent more than the next-best team) with a gaudy .843 OPS (the equivalent of the entire lineup hitting like Colorado All-Star Charlie Blackmon).

That unique and fortuitous combination of an elite bullpen and elite late-game offense has resulted in a number of late-inning comebacks — most notably a 13-10 win over the Rangers last month where the A’s came back from a 10-2 deficit after six innings.

And can you imagine how well-served the A’s would be with the combination of lock-down pitching and clutch hitting in late-inning situations come playoff time?

In this era where starting pitchers are throwing fewer innings than ever and batters are hitting a record number of homers, I can’t imagine a better formula for victories in October.

But despite all that excellence, there’s an important — perhaps the most important — ingredient of the A’s special sauce that’s missing. And it’s critical to the A’s getting to this point and continuing their success over the next two (plus?) months:

“You can’t quantify chemistry in analytical terms, but good chemistry on a ball club enables players to play up. I’ve seen it before — not quite at this level — we’re playing up. Guys are trusting each other — the pitchers are trusting me to put down the right fingers and it’s been a lot of fun,” A’s catcher Jonathan Lucroy, who was signed late in spring training, said earlier this week. “I kind of noticed it as soon as I got here. Our facilities aren’t the nicest in the world, our stadium isn’t the nicest in the world, the dugout is not the nicest in the world, but we go out and play and have fun. It’s very blue collar, it’s different. It’s pretty cool. I think it plays to our advantage.”