For the last 50 games, the Tigers haven't featured a traditionally functional starting rotation. That's in large part because they’ve barely had a rotation at all.

In the span of two weeks in July, Detroit lost starters Kenta Maeda (demoted to the bullpen on July 11), Reese Olson (injured on July 20), and Jack Flaherty (who made his final pre-trade start on July 24). At that point, the Tigers were three games under .500 (50-53) and six games out of a playoff spot.

In the 50 games since that final Flaherty outing, no rotation has thrown fewer innings, with a gap of 15 fewer than the White Sox, and 45 fewer innings than any team not on pace to set the Modern Era record for losses. In those 50 games, Detroit has used 11 different starting pitchers. They’ve also had the most wins in the American League, and allowed the fewest runs in baseball, and now they are tied with the Twins for the third AL Wild Card berth (although Minnesota owns the tiebreaker between the two teams).

You’d expect performance like that to be the result of a whole team contributing, and the lineup has certainly shown signs of life now that Parker Meadows, Riley Greene, and Kerry Carpenter are healthy and producing. That said, the offense has been more OK than great – just 15th in runs scored since the start of August. It’s about the pitching.

It helps, of course, to have Tarik Skubal, who is all but certain to win the AL Cy Young Award. Yet he’s been the lone established starting pitcher in this group, which is the best run prevention unit of the second half, and one of the best pitching staffs in Tigers history. It’s not exactly how you’d plan it. But it’s working.

How? And who are these guys who have led them back into the thick of the playoff race? (All numbers below are through Wednesday's games.)

The day after Flaherty made his final Tigers start, the club deployed reliever Tyler Holton as an opener in Cleveland. Holton threw two scoreless innings, then gave way to five different Tiger pitchers, who combined to shut out the Guardians, 3-0. Rather than being a one-off, it’s more like something of the norm. Look at how manager A.J. Hinch has had to mix and match his starting pitchers over the last 50 games.

Tigers games started, since July 25

• 10 // an ace (Skubal)
• 10 // an inconsistent rookie (Keider Montero)
• 10 // an opener (Beau Brieske)
• 5 // a since-demoted opener (Alex Faedo)
• 5 // another opener (Holton)
• 4 // a former No. 1 pick working back from injury (Casey Mize)
• 2 // another opener (Brenan Hanifee)
• 1 // another opener (Mason Englert)
• 1 // a rookie making his MLB debut (Ty Madden)
• 1 // a rehabbing starter limited to short outings (Olson)
• 1 // a spot starter (Brant Hurter)

It’s not exactly “Verlander, Scherzer, Porcello, Sánchez, and Price,” is it?

It's the above collection of names that has driven the lack of innings eaten. As we noted, the Tigers have the fewest innings out of their starting rotation by far.

Fewest rotation innings since July 25

• 186.1 // DET <<---
• 210.1 // CHW
• 231.2 // TB
• 236 // TEX
• 239.1 // MIA

But as we said at the top, the Tigers have allowed the fewest runs in the game despite that tattered rotation.

Fewest runs allowed since July 25

• 168 // DET <<---
• 172 // TB
• 175 // NYM
• 177 // HOU
• 187 // SF

These things don’t happen by accident, mostly. Let’s trot out four standout reasons for what’s going on with the Tigers' pitching -- aside, of course, from the transcendent Skubal.

1. The defense is better.

Run prevention isn’t just pitching, right? It certainly helps that a defense that had been mediocre in the first half has been considerably stronger in the second half.

It’s partially about the trio of Matt Vierling, Spencer Torkelson, and Javier Báez being -10 OAA in April yet +2 in September, as Báez is out for the season due to injury, and Vierling is spending a lot less time at third base (where he rated poorly) and a lot more time in the outfield (where he’s solid-to-average). It's partially also about Parker Meadows returning to cover every bit of grass in center field.

But it’s about in-season improvement, too, particularly with rookie second baseman Colt Keith, who endured a mid-season fielding slump (-4 OAA in June) and has been excellent ever since (+7 from July on), as well as from utility man Zach McKinstry and unexpected shortstop starter Trey Sweeney (+2), a piece of the Flaherty return.

2. Avoiding that third time through penalty.

While this isn’t exactly the way the Tigers might have wanted to plan it out, using openers and relievers in this way does allow them to avoid the dreaded ‘third time through’ effect, which states that pitchers become less effective the more times a batter sees them. For example, this year across the Majors, starting pitchers have allowed a .697 OPS the first time through, then are 34 points less effective the second time through, and 30 additional points less effective the third time through, up to .759. It’s the single most impactful thing keeping starters from working deep into games.

All this mixing and matching has allowed the Tigers to mostly avoid those dangerous third-time-through (TTO) plate appearances. Entering the day of the Flaherty trade, Detroit pitchers had the 20th-most TTO plate appearances. Since, that’s down to 28th-most, or third-least.

That’s nice, but it’s more than that, too. It’s not just fewer TTO plate appearances, it's also that the team has performed much better in the ones they’ve had, dropping from a .786 OPS against to a .627 OPS, which is a huge improvement. That, as you’ll see in a minute, is a little about good fortune – about the obvious eye test that everything is going right at the moment – but also about what the opener strategy allows the team to avoid.

Consider this: Part of the reason the TTO effect exists is because when the pitcher gets to that third time around, it’s not just that hitters are seeing the same pitcher again; it’s that the top of the lineup, which should be the opponent’s best hitters, are seeing them again. By having a reliever start the game, the “bulk pitcher” who comes in after would then be facing the middle or bottom of the lineup when his third time comes.

• Through Flaherty’s last game
  78% of Detroit’s TTO PA came against top 5 of lineup (16th most)

• The last 50 games
  70% of Detroit’s TTO PA came against top 5 of lineup (2nd least)

So the Tigers have reduced those dangerous third-time-through plate appearances, and they’ve made the ones that are remaining less risky, by having them come against the best hitters less often.

There’s a cost to all of this, obviously – the Tigers' bullpen has been heavily used. There’s a reason teams don’t do this all season long. But it’s not all a fluke, either.

3. Keider Montero has been far more successful.

It’s also in part due to the progression of Montero, who had posted a 5.03 ERA for Triple-A Toledo early in the season and was all of 36 2/3 ineffective innings (6.38 ERA) into his Major League career at the time this 50-game run began. He’s posted a 3.05 ERA in his last eight starts, he’s currently riding a 15-inning scoreless streak, and he was recently named AL Player of the Week.

That’s in part due to a new sinker he added in early August, which now represents 20% of his offerings to righties. Now: Should you really buy into a pitcher who has a mere 11% strikeout rate in September, one of the lowest strikeout rates of any regular starting pitcher? No, you should not, which brings us to …

4. Good fortune has been on their side.

It’s also in part due to simple good luck, which is less disrespectful than it sounds -- of course this had to be part of it. Sometimes things go your way and sometimes they don’t, and it’s safe to say that for any team that ever serves as an elite run-prevention unit for this long, it’s going to be at least a little about some good-old-fashioned good luck.

The Tigers, in this stretch, have just a league-average strikeout rate, and the second-lowest BABIP in the game. Neither exactly points to an elite ability to keep runs off the board indefinitely.

But the point isn’t that the Tigers are guaranteed to keep this run going forever, both because they’re not, and because they don’t need to. There are only nine games left in the regular season. Skubal should start two of them, Montero two more, and also six of them come against the collapsing Orioles and the White Sox and their worst-in-baseball offense. If they manage to get to the postseason, then Skubal and their top relievers can take up a larger share of all the innings. It doesn't have to work indefinitely. It just has to work for a few more weeks.

As of Thursday evening, the Detroit starting pitcher for Friday night's game against Corbin Burnes and the Orioles is listed as: TBD, ahead of an Olson start on Saturday. It's perhaps the most appropriate possible listing for a most unexpected run to contention.