Hi there! This next part of this “preparing our radars” miniseries in the Making Percentile Radars is the defender radar. I explained the rationale behind these radars in the previous post and went over the first type of radar we are making, so check that out if you haven’t already! Of course, all these metrics are taken from fbref and adapted to adjust for playing time and converted to percentiles. With that out the way, let’s go into more detail on what’s involved with the defender radar.

The Defender Radar

A defender’s primary role within the team is to prevent the opposition team from scoring goals. To achieve this, defenders must be adept at anticipating the movements and decisions of opposing players and possess strong physical attributes to win possession of the ball - either on the ground or in the air - for their team. Despite defending being their primary role, defenders are often required to progress the ball forward to their attacking teammates and so composure and good decision making in-possession are also key for a good defender.

Metric 1: Core Defending

The first collection of metrics we’ll look at is core defending. The first of these is blocks per 90. Blocks refers to any time where the defender blocks a pass or shot with their body. This provides a good indication of how well the player is protecting their goal and penalty area from either attempts on goal or from dangerous final-third passes. It should be noted that the defensive tactics of a team will bias the number of blocks a player makes and so this stat is not necessarily an ideal indicator of ability to block the ball. The next metric is the percentage of dribblers tackled. A dribble is when a player progresses the ball whilst in possession of it. Attackers will often attempt to dribble past defenders to disrupt their shape and fashion an opportunity to pass or shoot. So defenders who are able to tackle dribbling attackers more often do a better job at stopping opposition attacks. The last metric is interceptions per 90. Similar to a block, an interception is any time where the player wins possession for their team by intercepting a pass. As such, an interception must result in the player gaining possession of the ball, not merely blocking its intended path. Interceptions give a good indication of how capable a defender is at anticipating opposition decisions. Together, these three metrics provide a core foundation for a player’s defensive ability.

Metric 2: Passing ability

Once possession is gained by a defender, they must use their newly-won possession of the ball to good effect by successfully finding a teammate to progress the ball into an attacking situation. As such, the ability to pass well is an important attribute for defenders. The percentage of total passes completed is the first metric in this category. By dividing the total number of successful passes made (passes that find a teammate) by the total number of passes attempted, we get a measure of passing accuracy, giving an indication of how effective a defender is at finding a teammate with a pass. However, different tactical styles will change how accurate a player’s passing is. A team who do not encourage their defenders to make short, low-risk passes will tend to have a lower pass success rate - again tactical differences are important when interpreting individual player data.

The next metric is progressive passes per 90. A progressive pass is just any pass which advances the ball forwards by a certain defined distance (e.g. 30 yards). This helps to determine whether or not the player is making low-risk passes to nearby players or they tend to make more “progressive” passes to initiate attacks. In addition to progressive passes, to account for the attacking tendencies of wide defensive players, crosses per 90 is also included in this category. A cross is just a lofted pass from a wide position played into the opposition’s box - wide defenders often advance down the flanks to provide crossing opportunities.

Metric 3: Creativity

In keeping with the notion that there is more to a defender than simply defending their own goal, creativity metrics give insight into how productive a defender is in the attacking phase of play. Assists per 90 tell us how often the defender passes the ball to a teammate that then immediately goes on to score, giving a clear indication of goal creation ability. Expected assists per 90 are similar but instead tells us, on average, how many assists the defender should have based on the attempts on goal their assisted teammates have. To give an example of how these metrics work together, a defender with high expected assists per 90 but low assists per 90 is creating lots of or good quality (or both) chances for their teammates but their teammates simply are not converting those chances. Building on these metrics is shot-creating actions (SCA) per 90. SCAs are a broader version of assists, taking into account any direct or second-order player actions that result in a shot being taken by themselves or a teammate - SCA give a more holistic view of the creative contributions of a player but as with many of these metrics can be influenced by team tactics.

Metric 4: Aerial ability

Just one metric for this category - the percentage of aerial challenges won. Defenders, especially central defenders, must be adept at winning possession of the ball whilst the ball is in the air - having a high aerial win percentage tells us that a defender is aerial dominant and can be relied upon to protect their goal or win possession in physical aerial duels.

Metric 5: Defensive mistakes

To wrap up with the defender radar, we’ll consider two more metrics that can be considered measures of defensive error. It is important for defenders, and any player really, to cut mistakes out of their game. Fouls committed per 90 tells us how often a player makes an illegal challenge, potentially costing their team through providing the opposition with possession and set-piece chances. Mistakes leading to shots per 90 is particularly relevant for defenders as good levels of concentration and decision making are needed to avoid losing possession in dangerous areas and conceding chances (or even goals).

Conclusion

So that’s our defender radar, covering the key defensive metric as well as considering secondary responsibilities to the team that defenders have along side protecting their goal. Next time, we will explore the midfielder radar! Thanks for reading :)