Armchair Analyst: Tactical preview of Sounders-FC Dallas in Western Conference Semifinals

Matt "the Armchair Analyst" Doyle breaks down all of Sunday's first legs of the Conference Semifinals of the Audi 2015 MLS Cup Playoffs. Check them all out. 

EAST: DC-New York| Montreal-Columbus| WEST:Portland-Vancouver | Seattle-Dallas

The old and the young:

We can all see Ivanschitz in Pappa's place there, right?

How to solve it:Force the third man wide

Seattle are always more dangerous when one of their wide midfielders can cut inside and turn the attacking duo into a triumverate. Pappa, when dialed in, is excellent at it -- but he's also one who can drift out of games entirely when marked tightly. Valdez is less a facilitator than a back-post opportunist.

So Dallas have to take Ivanschitz out of the game and make him love that touchline. Really, truly force Dempsey and Martins to do it on their own.

What Dallas Will Do:Make Magic

When folks talk about FC Dallas players and their propensity to take opponents off the dribble, the guy they're really referring to is Fabian Castillo. He goes 1-v-1 way more than anybody in the league, leading MLS in dribbles attempted (265) and completed (114). He is a weapon.

He does not lead the league in success rate amongst high-volume dribblers, however. That distinction belongs to a teammate:

Bear in mind that not all "dribbles" are created equal. Fullbacks usually score high in the "success rate" department because they receive the ball on the run with only one defender in front of them. Defensive midfielders also tend to do well because they're selective about when they try to dribble an opponent - it's usually only attempted when the opponent has been pulled off-balance, caught in the sway of someone else's attacking gravity or spun like a top by good ball movement.

For players like Ceren, for example, it's about picking the right moment and hitting the gap. For players like Diaz, it's about clowning any defender who comes within five yards, and then turning that into a chance:

How to solve it:Pray Alonso is healthy

Ozzie simply doesn't allow that sort of nonsense. Yes, he'll drop a couple of fouls if he needs to, but the truth is he's preternaturally gifted with quickness and balance, and has the soccer IQ to understand the right angles to take when closing down a central midfield attacker. He doesn't bite on the feints and fakes that leave lesser players in the dust.

If he's not out there, I think Diaz ends up having a big game. And that's nightmare fuel for the Sounders.

These two teams played a tight and memorable series last season, one in which Seattle advanced only on away goals. Dallas technically did not lose a game in last year's playoffs.

They're a year older and better, and Diaz is healthier. I'm not going to pick them to win this game outright, but they're strong favorites to win this series.

The only caveat: It feels wrong to pick the team that starts David Texeira as a lone No. 9 over the team that starts Dempsey & Martins up top. Tex has been serviceable, but most of his goals have come against subpar opponents, and he's clearly not at the elite level of ObaDeuce.

You need an elite striker (or two) to win an MLS Cup. LA had Robbie Keane; Sporting KC had Dom Dwyer; Colorado had Conor Casey; RSL had Yura Movsisyan.

If Seattle win, it'll be because ObaDeuce were simply too great to contain.