Analyzing Defender Value by Role (Part 3)

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Ekon Ayo is a fullback defender in the SSL academy S25 class.  New to the league, Ekon wants to grow into a defensive specialist for his club, but he doesn’t yet have a good sense for how he should prioritize his development to get there.  Over this series of articles, he learns the defensive behaviors that he should replicate to maximize value at his position.

Part 1 outlines the defensive stats
Part 2 analyzes the defender roles on the pitch
Part 3 considers broader team success
Part 4 dives deeper into center backs
Part 5 identifies role model fullbacks for Ekon
Part 6 focuses on wing backs
Part 7 appreciates defensive midfielders
Part 8 looks at differences in the minor league

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PART 3
TEAM SUCCESS MATTERS

Part 2 of this series presented a stats comparison between the four defensive roles.  As discussed in part 1, it’s important to consider that defensive activity recorded in the box scores might be biased by the strength of the defensive unit as a whole.  Defensive stats would ideally be adjusted for opponent time of possession so that all players are judged equally for the rate at which they make plays, but adjusting for time of possession is logistically difficult.

There are other team-level statistics that can fill in for time of possession and provide additional context about a defender’s performance without directly adjusting the defensive play data.  After all, stopping an opponent from scoring speaks to the strength of each individual defender, not just the abilities of the entire defensive unit together.  The SSL game summaries include the following marks for the team’s defense:

• A shot conceded is a goal attempt made by the opposing team, which may or may not be a shot on target conceded and may or may not result in a goal conceded.
  
• A match’s expected goals conceded is an advanced measure of the quality of the opponent’s total scoring chances based on factors like the distances, angles, and play types of their shots on goal.
  

Ultimately, the objective of the defense is to limit goals scored, regardless of how many presses, tackles, interceptions, blocks, or clearances it takes to do so.  Defensive actions carry value only if they support the broader success of the team.  The radar plot below is the same as the plot in part 2 but only includes defenders on clubs that conceded fewer than 50 goals in S23 (Hollywood, União, Tenochtitlan, Reykjavik, Shanghai, and Liffeyside – 14 CBs, 8 FBs, 4 WBs, 13 DMs). 



The plot doesn’t change dramatically when including only the top defenses in S23.  Fullbacks logged more blocks per 90, wing backs were less aggressive, and center backs had fewer shots blocked.  But all things considered, defensive players have similar assignments regardless of the broader success of the team.

It’s impossible to say whether these differences in defensive behavior are the cause of conceding fewer goals or the result of playing with a better defensive unit.  Fullbacks creating more blocks might be an important way to limit shot attempts, or maybe it is just an indication that better defenses don’t allow attacks into the center of the pitch and force more activity to the outsides.  The lower aggression of the wing backs observed here might indicate that playing more conservatively is a better strategy, or maybe it simply tells us that wing backs don’t need to play as aggressively if the defensive unit is better at maintaining shape and possession.  Either way, valuable defenders are those that play to the needs of their role.

Continue to Part 4: The Defensive Anchors