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Seattle’s defense is 10 deep, according to expected Goals Against

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And with those ten, it’s very, very good

The Seattle Sounders are hot, having earned 27 points in their past 13 games. They weathered the storm of early season lineup nightmares and are tied for 1st in the West on points. This is a far cry from the first 10 matches of the season in which the team only earned 10 points. With 10 matches to go before the playoffs, it seems to be a good time to look at this team and ask ourselves what we have in store for the reason of the season.

With the dust having settled after the transfer window, there appears to be a clear ideal XI with a couple players sprinkled in for depth-with-no-drop-off. Unfortunately, with the return of Osvaldo Alonso in this past weekend's match, the soccer gods have demanded Brad Evans and his back as sacrifice, so for the first time this season we are denied having our best 15 players healthy at the same time.

Health has been an issue. International call-ups have been an issue. To say that the 2017 season has tested the depth of the Sounders would be an understatement. For the sake of this article, I want to look at how the Sounders have performed defensively with different defensive groupings and what it means for us moving forward. Keep in mind, I'm only looking at starters here, not substitutes, except for the match away at Colorado where both Alonso and Chad Marshall left early to injuries.

Stefan Frei has been between the posts for every match this season except for one, where Tyler Miller replaced him. The Sounders have started 10 different players in their four defensive positions;

  • Six Right Backs: Gustav Svensson, Oniel Fisher, Jordy Delem, Cristian Roldan, Brad Evans, and Kelvin Leerdam.
  • Four Centerbacks: Roman Torres, Chad Marshall, Tony Alfaro, and Svensson.
  • Three Left Backs: Joevin Jones, Nouhou Tolo, and Fisher.

For their two defensive midfield spots (ignoring the tactical inaccuracy of that nomenclature), the Sounders have started four players: Alonso, Roldan, Svensson, and Delem. In the aforementioned Colorado game, Aaron Kovar replaced Alonso in the 17th minute, but he moved to Right Wing, shifting Nicolas Lodeiro to Left Wing, shifting Joevin Jones back more centrally, though he didn't really stay central.

12 players for 7 positions: GK, RB, CB, CB, LB, DM, DM. The question I was asking myself was how has the team performed when it's had an ideal starting back 7 versus a less-than-ideal starting back 7.

This question wasn't easy to answer initially, as first I had to establish who my ideal starting back 7 were exactly. Eventually I landed on my starting parameters being the following: GK - Frei; RB - Evans/Leerdam; CBs - Marshall & Torres; LB - Jones; CDM - two of Alonso/Roldan/Svensson. I will refer to this group of nine players in these seven positions as the Ideal-7.

This group of Ideal-7 has played together a grand total of four times this season. Four times in 24 games. Home against Houston Dynamo and Sporting Kansas City, and away to Portland Timbers and Minnesota United. In those four games the team has earned 10 points and has a +6 Goal Differential. They're legit, and if we can keep playing them for the rest of the season, we're in good shape moving forward.

But that leaves us with 20 other games where we haven't played an Ideal-7, and what happened in those 20 games I find to be very interesting.

Knowing we have 20 out of 24 games played with a less than Ideal-7, I wanted to break it down further: what if we had 6 of 7 positions started with our Ideal-7, what if we had 5 of 7, 4 of 7, 3 of 7, etc. One thing to keep in mind is that the sample sizes for these occurrences are not large.

7 out of 7 Ideal Starters - 4 Games

6 out of 7 Ideal Starters - 8 Games

5 out of 7 Ideal Starters - 6 Games

4 out of 7 Ideal Starters - 4 Games

3 out of 7 Ideal Starters - 2 Games (this includes away to Colorado)

Exactly half of our games so far have been played with 6 or 7 of our Ideal-7 defensive starters. Conversely, the other half of our games have been played with 5 or fewer of our Ideal-7 defensive starters.

Okay, background set-up finished. Let's dive into the numbers.

WARNING: The rest of this article will talk a lot about Expected Goals. If this bothers you, well, too bad, because I find it to be a useful resource despite its flaws.

Glossary of Terms

  • xGA - Expected Goals Allowed: This number, roughly, equates to the amount of goals the opposing team should have scored against Seattle in a particular game. For this article, I am looking at a per-game Average. Not a cumulative total. I used American Soccer Analysis xG by game data. There are a few different models out there. I chose this one.
  • GD - Goal Differential: This is purely our Goals Scored For minus our Goals Scored Against. In a 1-0 Sounders Victory, this number would be +1.
  • PPG - Points Per Game: This number, ranging from 0.00 - 3.00 is the average number of points the Sounders score per game. Games can result in 0 points for losses, 1 point for draws, and 3 points for victories.

Sounders Season

  • Games: 24
  • xGA: 1.37
  • GD: +5
  • PPG: 1.54

7 of 7 Ideal-7

  • Games: 4
  • xGA: 0.95
  • GD: +6
  • PPG: 2.50

6 of 7 Ideal-7

  • Games: 8
  • xGA: 1.13
  • GD: +4
  • PPG: 1.88

5 of 7 Ideal-7

  • Games: 6
  • xGA: 1.68
  • GD: -3
  • PPG: 0.67

4 of 7 Ideal-7

  • Games: 4
  • xGA: 1.22
  • GD: -1
  • PPG: 1.25

3 of 7 Ideal-7

  • Games: 2
  • xGA: 2.54
  • GD: -1
  • PPG: 1.50

Some astute readers might note that our GD here only adds up to +5 while our season currently rests at a +6 GD. This is because Own Goals do not count for ASA’s xG purposes, so our 3-0 victory over LA Galaxy earlier this season counts as a 2-0 victory.

Looking at this is all well and good, but what does it mean? In simple and obvious terms, it means that the more Ideal-7 players who start for the Sounders, the better the team performs. Duh.

The numbers bear this out. Earlier I mentioned the Sounders have started six or seven of their Ideal-7 12 times this season, and 12 times this season the Sounders have started five or fewer of their Ideal-7. As a reminder the squad is deep enough that there are nine players in the Ideal-7 defense (this number is about to grow to ten players). Here are those numbers:

6-7 of 7 Ideal-7

  • Games: 12
  • xGA: 1.07
  • GD: +10
  • PPG: 2.08

5 or fewer 7 of Ideal-7

  • Games: 12
  • xGA: 1.67
  • GD: -5
  • PPG: 1.00

To put some of these numbers in context, the best defense in the league right now is Sporting Kansas City. Their xGA is 1.02. The second best defense in the league is FC Dallas. Their xGA is 1.13. If the Sounders maintained a 1.07 xGA for the season, they would have the second best performing defense in the league.

So moving forward the best strategy would be for the Sounders to play their best players. Got it. But who truly are the best players? Have other players inserted themselves as preferential starters over incumbents? Are the Sounders better with Nouhou at LB than Jones? How bad was Delem as a RB? Diving into these questions allowed me to uncover an interesting truth.

The Sounders have a below average defense when any of Alfaro, Delem, or Fisher have started. It doesn't matter if there's one, two, or three of them. In the games those three players have started, the Sounders have struggled on defense.

That's it.

It doesn't matter if Svensson starts at CB, RB, or CDM. It doesn't matter if Tolo is playing LB with Jones pushed up. It doesn't matter if Roldan making an emergency spot start at RB. What matters is that Alfaro, Delem, or Fisher don't start.

Let's look at some more numbers.

When Alfaro Starts

  • Games: 7
  • xGA: 1.79
  • GD: -5
  • PPG: 1.14

When Delem Starts

  • Games: 8
  • xGA: 1.59
  • GD: 0
  • PPG: 1.38

When Fisher Starts

  • Games: 6
  • xGA: 1.50
  • GD: -6
  • PPG: 0.67

The one caveat here is the following: Tony Alfaro did not start against Colorado, but I am including him as a starter since he replaced Chad Marshall in the 22nd minute. Most of what Colorado accomplished in that game came after this replacement.

Now you add up those games and that's 21, however on multiple occasions these players have started together. Ultimately, however, that doesn't matter. The numbers don't change drastically whether one, two, or all three of these players start together (and the sample sizes don't really allow for quality analysis). What's important here is this: the Sounders have played in 12 games where one of these three players started. This means that the Sounders have also played in 12 games where none of these three players started. Let's look at how that breaks down.

When Alfaro - Delem - Fisher Start

  • Games: 12
  • xGA: 1.69
  • GD: -6
  • PPG: 1.00

When they don't start

  • Games: 12
  • xGA: 1.06
  • GD: +11
  • PPG: 2.08

Wait a second, that looks familiar...

scrolls back up, rests chin in palm, eyebrows raise in surprise

When Alfaro - Delem - Fisher don't start

  • Games: 12
  • xGA: 1.06
  • GD: +11
  • PPG: 2.08

6-7 of 7 Ideal-7

  • Games: 12
  • xGA: 1.07
  • GD: +10
  • PPG: 2.08

but wait...

When Alfaro - Delem - Fisher Start

  • Games: 12
  • xGA: 1.69
  • GD: -6
  • PPG: 1.00

5 or fewer 7 of Ideal-7

  • Games: 12
  • xGA: 1.67
  • GD: -5
  • PPG: 1.00

Here's what this all means: the Seattle Sounders cannot afford multiple injuries in the back seven. With Evans down, we've lost our primary RB backup and one of two CB backups. If Leerdam is out while Evans is still hurt, Roldan and Svensson should be your only options at RB. However, Svensson is also our only viable option at CB should either Torres or Marshall miss time. If Jones misses time, Nouhou is our man there. Our nine players making up our Ideal-7 is now effectively 10 players, plus with a bit more positional flexibility with Roldan and Svensson.

The 10 players making up the Ideal-7: GK - Frei; RB - Evans/Leerdam/Roldan/Svensson; CB - Marshall, Torres, and Svensson; LB - Jones & Nouhou; CDM - Alonso, Roldan, Svensson.

The introduction of Callum Mallace allows a bit more flexibility in moving Roldan and Svensson along the back line in times of need, as the newly acquired box-to-box midfielder can hold down the DM spot. Until Evans returns, if Evans returns, there may have to be some creative lineup shuffling should other injuries occur. This also really shines a light on how poor of a decision it was to start the season out with Brad Evans as the primary RB with Fisher as his backup. Oops.

Given what we now know, under no circumstances should Alfaro, Delem, or Fisher start. If the Sounders can remain healthy, with a resurgent offense and a shutdown defense, they're primed to make another deep run.