We're down to the final four of the Audi 2021 MLS Cup Playoffs, and the tournament's increasing unpredictability is making the prognostication game a tricky one.

After the home favorite won the first five games of this postseason, the road dogs have taken four of the last five. That run of upsets has left the field without most of the supposed top contenders as we head to the Conference Final stage.

For the second round in a row, the last game on the slate ended with penalties dooming me to a red mark in the ledger. That Revs loss to NYCFC dropped me to 2-2 for the Conference Semifinals, and to a slightly unsatisfactory 6-4 overall.

In the year of the postseason upset, let's see if I can finish strong heading into this weekend's Conference Finals.

(4) Portland Timbers vs. (7) Real Salt Lake
Western Conference

WHEN: Saturday, Dec. 4 at 6:30 pm ET
WATCH ON: FS1, FOX Deportes

If anybody had these two clubs as Western Conference finalists on their bracket, well, you may be an oracle. To get here, each team has gutted out at least one road victory and clearly outplayed a worthy foe. Ordinarily, I'd simply take the Timbers at home and be done with it.

Except "ordinarily" they'd have Sebastian Blanco and Dairon Asprilla to make good things happen in the final third, and neither will be in uniform for the Western Conference Final. So Portland's wings are clipped at the same time Real Salt Lake should have Albert Rusnak back available for selection. That's too big of a playmaking differential swing to ignore, and suddenly you find yourself easily swayed by RSL's Cinderella charms.

While the Claret-and-Cobalt at times benefitted from Seattle's wastefulness, their defense was only rarely ripped apart. In the Conference Semifinal, RSL shut down Sporting KC as few teams have. Aside from Johnny Russell's penalty kick, the home favorites only managed two shot attempts from inside the box, and both were blocked. That's the sort of stifling defensive play that can handle a shorthanded Timbers attack. And Damir Kreilach with his band of crazies upfield can do the rest.

Prediction: A 2-1 Real Salt Lake victory sends them to MLS Cup for the first time in eight years.

(2) Philadelphia Union vs. (4) New York City FC
Eastern Conference

WHEN: Sunday, Dec. 5 at 3 pm ET
WATCH ON: ABC, ESPN Deportes

Thanks to NYCFC's newfound postseason nerve, another Supporters Shield winner has bitten the dust early. It's not much better to be a top conference seed in the Audi MLS Cup Playoffs – over the last three seasons, four of the six No. 1's stumbled at their first hurdle. That bye week can be a sneaky killer for top contenders.

And just like that, Philadelphia (the only team to win at home in the Conference Semifinals) have become the MLS Cup favorite. The Union are tough as nails all over the field and can play the string out in Chester, where they're on a 13W-1L-2D tear. Heck, if their strikers can relocate the ol' finishing boots, they might run away with the title.

A strong case can be also made by NYCFC, who are finally showing the mettle required to win dirty in the postseason. The Cityzens have even won on three of their last five visits to Philly. Unfortunately, they must go there this time without cobra head Valentin Castellanos, as the Golden Boot presented by Audi winner saw red late in the win at New England. Who's going to relentlessly work the Union center backs and wait to take the big chance? I honestly have no idea, which is a healthy portion of the reason this call is for Doop-A-Cero.

Prediction: A 2-0 Philadelphia win sends them to MLS Cup for the first time.