For the better part of this season I've worked with the operating assumption that FC Dallas are the best team in the league, an assumption that's been fueled by a few things:

• Mauro Diaz is magic. The Argentine No. 10 is prooooobably my favorite player in the league to watch because he has the soccer equivalent of "in-the-gym range" – there's no pass on the field that he can't hit. Dallas are built around that trait, which is as it should be.

• That said, they don't fall apart when Diaz isn't available, largely because they've had so much practice without him over the last three seasons. It would have been fair to describe him as "oft injured" entering 2016, and while Dallas weren't great when he was sidelined, they were pragmatic as hell and repeatedly found ways to pick up points.

• Thanks to their prolific academy, their consistently good work in the SuperDraft and the ability to find worthwhile pieces from Latin America, they possess a ton of depth. That's crucial for a team that has designs on a Supporters' Shield.

• Said depth mostly is players in, or just entering their primes. As so:

Pulled this together on MLS team-age breakdowns pic.twitter.com/eRgykxu2OF — Tom (@Worville) August 31, 2016

Young-ish players are better suited to weathering the rigors of the long and cold, then hot, then cold again; and sometimes on turf; and sometimes at altitude; and sometimes in a hailstorm MLS season than those with a few more miles on their legs. Steven Gerrard, for one, talked about his shock at the week-to-week adjustments required by this league, and he's certainly not alone.

This isn't to say that older players and teams can't succeed, as NYCFC are intent upon proving at the moment. But the smart money has been on younger legs from the start.

• They had a game-breaking talent on one wing (so long, Fabian) and a reliable goalscorer on the other (hello, Michael – and I will come back to this point a little later).

Right there is where it gets tricky, most obviously because Castillo is gone and won't be back this year, if ever. And to be fair, Dallas stumbled upon his departure, posting a 1-1-2 record in the four games following his egress after going 7-1-2 in his final 10 starts. Castillo left a hole that they arguably still haven't filled.

Still, they've found a way, and on Saturday night posted their second straight 3-1 win, this time over the visiting Portland Timbers. Dallas now have a seven-point Supporters' Shield lead with just six games left. It would be a shock if they didn't win it – just taking full points from their three home games would likely be enough. Depending on how the US Open Cup final goes on September 13 (they'll host the Revs), said Shield will either be Dallas's first major title in six weeks or their first major title in 19 years.

It's a pretty big deal.

• They have the Defender of the Year in Matt Hedges. All due respect to Jelle Van Damme and Drew Moor, both of whom have been crucial to their teams, but Hedges is the best backliner in MLS this year. Dallas are 11-3-6 with a +16 goal differential when he plays, and 4-4-0 with a -7 goal differential when he doesn't.

Simply put: He is fantastic at cutting down passing lanes individually, and has a reputation as one of the best organizers in the league, so Dallas are among the best at denying options A, B & C:

Valeri created 0 chances, and the only two passes he completed into the box were a pair of set pieces. #RCTID pic.twitter.com/dDHDhfqT1I — Chris Rifer (@ChrisRifer) September 4, 2016

(For a Timbers-centric view of this, click HERE)

Sometimes correlation isn't causality, but in this case it is. If Diaz is the keystone, Hedges is the cornerstone.

• Thanks to Diaz and Hedges, and especially Walker Zimmerman, Dallas are dominant on restarts. For as much praise as Oscar Pareja gets and deserves for how aesthetically pleasing this team is, they are arguably better on dead balls than they are from open play.

• Add in solid fullbacks and mistake-free deep-lying midfielders, and you have the whole list of "why I think Dallas are the best team in the league this year, and thought so entering the season." The only reason I didn't pick them to win the Shield outright is because I expected the Western Conference to be much better than the East, but that hasn't really been the case.

Even great teams have flaws. With that in mind, here are the questions I've had about Dallas since Day 1 – and you'll note that they're related:

• Can a team without a top-tier No. 9 win a Shield? Maxi Urruti has had his moments, but he's clearly sub-elite in this league, and that flies in the face of recent title winners. You need a guy like Fanendo Adi or Bradley Wright-Phillips or Gyasi Zardes or Dom Dwyer or Obafemi Martins to win titles in recent-vintage MLS, and FCD are still without that.

• Can Castillo and Barrios make up for the lack of goalscoring from up top?

In early July I thought "yes." Then Castillo left and I thought "no." And now... now it might not matter, since Dallas are repeatedly discovering new answers. Barrios has two goals in the last two months – both came last week against Houston – so it's not like he's carrying the load, and none of the young forwards on the roster have threatened to unseat Urruti, who still runs hot-and-cold. It's been offense-by-committee, with big goals from Urruti and Diaz and Barrios and Zimmerman and Victor Ulloa and so on and so forth until the rising tide of inevitability submerges all counterarguments.

Dallas may in fact become the first team since the 2008 Columbus Crew to win a Shield without having a double-digit goalscorer. Barrios currently leads the team with eight and Urruti has seven. You could also argue that Tesho Akindele, with six goals on the season, has a shot at getting to 10, but it's not a great one.

The key takeaway, though, is that it didn't matter for that Crew team, and it's looking very much like it won't matter for Dallas. They've been the best team most of this season, and as of this weekend – with the stretch run dead ahead – they're officially, unmistakably the favorites.

A few more things to ponder...

5. I mentioned NYCFC above, and they will spend another week atop the Eastern Conference standings following Thursday's dramatic 3-2 win over D.C. United.

But man did they dance with the devil in this one. It took three missed D.C. sitters, an incredible back-pass and a fortunate deflection on the winning feed to come away with all three points. Good teams make their own luck, of course, and credit to NYC for making more than their fair share all season.

4. The other team in that market have been something in the neighborhood of "unlucky" with their road results, but then reversed that entirely with Saturday's 1-0 win at Vancouver. It was just RBNY's second road win of the year and they managed it despite conceding chance after chance after chance to 'Caps forward Erik Hurtado.

"I just said to the guys in there, how'd you feel? Tell me what you saw at the end of the game," said Whitecaps head coach Carl Robinson afterward. "And they said we'd done everything boss, we give you everything, we created, we just didn't score."

Robinson's not wrong. The game itself can be cruel.

3. New England crept up to within two points of D.C. for that final playoff spot in the East after their pretty comprehensive 2-0 win over visiting Colorado. There were better passes than these from this past week:

Goal drought no more. @JuanAgudelo puts the #NERevs in front with a smooth finish off the post. #NEvCOL https://t.co/397ZDWOMhx — Major League Soccer (@MLS) September 3, 2016

...but I'm still giving that sequence our Pass of the Week because it so clearly defines what the Revs want to do in attack as a team. When they're clicking – as they were in this one – they are the league's best team in tight spaces.

2. The Galaxy finally snapped their winless skid with a 2-1 win over Columbus at StubHub Center. LA continue to be a much better attacking team in the 4-4-2, which is what they trotted out in for the majority of this one.

1. And finally our Face of the Week comes from Chicago's 3-0 win over the Union:

The Fire are now 2-2-1 in their last five, and have scored 12 goals in that span while playing mostly pretty good and fun soccer (save for the hour they played a man down against D.C. last week). They are still very much an absorb-and-counter team, but the movement and chemistry of strikers Luis Solignac and Michael De Leeuw is now giving the previously overwhelmed midfield ample passing lanes and attacking options. "Absorb and counter" is a nice change from "absorb and absorb and absorb and concede."

This team will get at least one more big win that costs someone home field advantage come November, or even costs a playoff spot. For the first time in a long while Chicago are very much worth watching.