Monthly Archives: May 2013

Generating More Scoring Chances for Your Team in Soccer

What tactics should soccer coaches be using to generate more scoring chances in soccer? As I have mentioned in previous posts on this blog, each “soccer action” while in possession of the ball — meaning each dribble and each pass a player attempts — will have some chance the action will succeed and some chance it will be turned over. You commonly hear people refer to “50/50 balls” in this manner, but you can extrapolate from that common example percentages that might be applied to every other type of play, too. Whether it’s a midfield player dribbling in an open field without a defender near, a forward making a back pass, or a defender booting the ball upfield to get it out of danger, you can come up with some percentage figure for how likely each and every action is to succeed.

The interesting thing about thinking about soccer tactics this way is how these percentages of success for each and every play interact with one another. Keep in mind, your team’s objective is to move the ball down the field into scoring position near the opposing goal so your team can get a shot on goal and hopefully score. Starting with an overall chance of success of 100%, by taking the percent chances of success for each soccer action in your offensive build-up and MULTIPLYING them as a decimal, you will see that only one soccer action into your build-up (a pass or a dribble), even with a very high-percentage, safe play with a 95% chance of success, your overall chances of successfully taking the ball downfield into scoring position drop by 5% immediately, and will continue to drop by at least around 5-10% with each soccer action that extends the build-up.

  • 100% to start with multiplied by 90% equals 90%.
  • 90% multiplied by another 90% equals 81%.
  • 81% multiplied by another 90% equals 72.9%.
  • 72.9% multiplied by another 90% equals 65.6%.

That’s two high-percentage passes and two series of high-percentage dribbles, and already your team’s chances of success of completing those four actions, even with little to no defensive pressure (which is what the high-percentage of success should mean), and still your team only has an overall chance of success of barely 65%! If your team is starting out of the back, two passes and two dribbles may not even get them to half field, yet even taking only high-percentage, safe chances, your team still has barely better than 50/50 chance of retaining possession.

Next, let’s look at a series of more risky, yet still high-percentage chances of 80% chance of success:

  • 100% to start with multiplied by 80% equals 80%.
  • 80% multiplied by another 80% equals 64%.
  • 64% multiplied by another 80% equals 51.2%.
  • 51.2% multiplied by another 80% equals 41%.

Make four high-percentage passes in a row and still you have less than 50% chance of retaining possession! Amazing, huh?

So what can your team do to improve their overall chances of success in moving the ball downfield into scoring position?

  • Take care of the ball and don’t turn it over cheaply. Even high-percentage plays can lead to turn-overs and your team will likely need 10 to 20 soccer actions (combinations of dribbles and passes) to move the ball the length of the field.
  • Try to get turnovers as far up the field as possible because that reduces the distance your team needs to cover in order to get into a position to score.
  • Your team has to balance the urgency to move the ball forward with the need to make extremely high-percentage plays in order to retain possession and keep moving into a scoring position.
  • Don’t turn the ball over anywhere near your goal because that makes it much easier for your opposition to get the ball into scoring position.
  • Do not make ANY low-percentage plays because even just a single low-percentage play during your team’s build-up, and that build-up will likely fail.

Can the Concept of an “Error” Be Added to Soccer Statistics?

Much as errors in baseball and unforced errors in tennis, I believe keeping errors in soccer could lead to much more insight and understanding into the quality of a player. Scoring an error in soccer would be difficult and very subjective since failure in soccer happens so often as previously discussed in this blog, but that in no way would diminish the value of the stat since I have already shown in previous posts on this blog how important it is for players to make high-percentage choices while moving the ball downfield (and defending, too).

I personally think the concept of an error in soccer should be slanted more towards the concept of “unforced” errors since those I feel are more likely to show a lack of skill or a lack of quality decision making. Errors should also be kept for defense as well as offense.

Some common plays that could be examples of soccer errors:

  • An uncontrolled dribble moving up the field under little or no defensive pressure.
  • Losing a dribble in the defensive half of the field while dribbling towards your own goal.
  • A badly missed forward pass under little or no defensive pressure.
  • A missed backwards pass in the defensive half of the field.
  • A badly missed attempt to control the ball without any defensive pressure.
  • A wild shot on goal with little to no accuracy.
  • A failed defensive clearance that still leaves the ball in a dangerous position.
  • A goalkeeper badly misplaying a shot or cross.
  • Own goals.
  • Senselessly committing a foul, particularly when it results in a dangerous free kick within scoring range for the other team or when the foul ends your own team’s scoring opportunity.
  • A badly missed tackle.
  • Kicking the ball directly out of bounds on a corner kick or goal kick.
  • Not picking up a runner on defense allowing the runner to immediately receive the ball and get a shot off.
  • Playing a “hospital ball” to a teammate that might technically be considered a completed pass but puts the teammate in the crosshairs of a bad challenge from the opposition with little opportunity to do anything with the ball except try to survive the challenge without getting hurt.

What New Stats in Soccer Can Technology Give Us?

As technology such as GPS tracking of players on and off the ball become more prevalent, it becomes easier to analyze how much each player contributes to the buildup of the team moving the ball down the field in terms of passing, dribbling, and receiving passes. Geometrically, each pass and each dribble on the (X,Y) coordinates of the field has some deflection percentage towards or away from goal as well as the raw distance covered. Analytically, this movement could be seen in terms of direct distance to goal as well as positioning only based on the endlines and sidelines.

I believe soccer statisticians should consider some sort of averaged weighting between these two geometries of direct distance to goal versus pure (X,Y) positioning between the endlines and sidelines. Wide positioning near the endline is a threatening place for the team in possession to be because there is no way for the defense (particularly the goalkeeper) to keep the entire offense in view at the same time. With the ball out wide in advanced positions near the endline, the defense (particularly the goalkeeper) now have attacking players behind them and it is much harder to track the ball as well as the movements of all the attacking players. Crosses from these advanced and wide positions can be played to players in the blind spots of the defense, and it is easier to line up more than one attacker to play these crosses at the same time if the rest of the team has kept up with the play.

Playing the ball into wider positions (and even negatively) can be valuable for retaining possession and exhausting the defense. As previously mentioned on this blog, managing fatigue of your own team while making high-percentage plays to exhaust the defensive team can increase your chances of advancing the ball into scoring positions and ultimately scoring over the course of the game. For these reasons, I believe keeping track of the various aspects of raw distance, distance towards or away from goal, and distance towards endline and sideline could really lead to some nuanced player statistics. Especially if an overall percentage of success is attached to the distances.

For instance, from the center of the field, a 30 yard pass directly towards the opposing goal would have no deflection and the 30 yards of movement would be 30 yards towards goal as well as 30 yards towards the endline. A 30 yard pass directly towards the sideline from the center of the field would have no yardage movement towards the endline but 30 yards movement towards the sideline and actually would get further away from the opposing goal by about 7 yards. A 30 yard pass directly backwards towards a team’s own goal would be considered as purely a negative action on both scales of directly towards goal and directly towards endline. A 30 yard pass at any angle from the center of field would have varying amounts of positive and negative yardages towards the opposing goal and opposing endline (as well as positive and negative yardages associated with width) depending on the angle of the pass.

Dribbling I think should be treated in the same way as passing based on where the dribble starts and ends. Yardages for receiving of passes should also be kept with similar weighting between yardages directly at goal and yardages towards endline and sideline.

Lastly, and in some ways, most importantly, I think these yardages should be kept even when turnovers result, with the possible exception of pass receiving yardages. When the ball is passed down the field, even when the ball is turned over in the process, the ball is still advanced even though the team does not retain possession. Similarly with a dribble — even if the player turns the ball over at the end of the dribble, the ball has still been advanced (or maybe retreated). This allows the statistician to also apply the same statistics to all ball movement including shots and clearances as well since a player taking a shot does advance the ball (but it results in a turnover) and a player making a clearance knows that if they put the clearance in the right spot, their team will still be able to retain possession of the ball.

Since it is often possible to pick out the intended recipient of a pass even if it is not completed, some value could be found in keeping stats on incomplete pass reception yardages but it may be more hassle than it is worth with the amount of information to be found in the other available statistics under this analytical system. In particular, leaving out incomplete pass reception yardages eliminates the need to decipher the intention of a shot / cross, a clearance, or a badly missed pass.

How Does a Team Generate Scoring Chances in Soccer?

To generate a scoring chance in soccer, the team must first move the ball down the field to within about 25 yards of the opposing goal. From that range, the team then tries to get the ball in the ideal shooting position in front of a player that has some open space around them and a clear look at the goal. The focus of this post will be how the team can move the ball down the field to get a scoring opportunity. Teams spend much of the game trying to move the ball into scoring position, so understanding how to do it well will greatly contribute to the quality of soccer the team can play. Whether the team takes the ball directly down the field in a quick, counter-attacking style of play, or whether the team takes a slow buildup of passing, or whether the team has star ball-handlers that can dribble through defenders, or a combination of styles, analytically you might see a percentage chance of success associated with each pass or dribble in the buildup.

Lets look quickly at several typical soccer buildups to scoring chances.

First, a quick counterattack initiated by the goalie. Let’s say the goalie punts the ball past half field to a forward making a run towards the corner flag, who then dribbles the ball towards goal to create a scoring chance. Putting some percentages of successful completion to these actions, let’s say the goalie punt past half field in this instance has a 40% chance of success, while the dribble another 40 yards downfield has no more than a 15% chance of success. Multiply these chances together and you have .4 x .15 or an overall chance of 6% of success in creating a scoring chance.

Second, another scoring chance initiated by the goalie, but this time, the goalie rolls the ball out to a wide defender, who dribbles forward a bit, kicks it to the center mid, who kicks it to the center back, and so on, in a slow buildup of 15 passes and some dribbling to get into scoring position down the field. Analytically, you might assume chances of success between 70-95% for these passing and dribbling actions moving the ball around the field eventually ending in a scoring chance. Starting with the rollout from the goalie this might look like:

  • .95 x .95 x .85 x .9 x .9 x .95 x .8 x .85 x .7 x .9 x .85 x .9 x .85 x .9 x
    .8 x .75 x .9 x .8 x .9 x .85
  • an overall chance of success in creating a scoring chance of 4.89%

Next, let’s look at a midfield turnover where the center mid who gains possession kicks the ball out wide to another midfielder, who then dribbles forward and passes to a striker near the opposing penalty box. Statistically, this might be:

  • .85 x .9 x .7
  • an overall chance of success of 53.55%

Looking at these series of buildups that might result in a scoring chance in soccer, a few things become evident.

Where turnovers happen on the field is important because turnovers closer to one’s own goal are much easier for the opposing team to convert into legitimate scoring chances simply because they have less distance to move the ball to get into scoring position. Turnovers in one’s own penalty box or just outside result in an immediate scoring chance for the other team.

Each player making smart decisions when in possession of the ball can greatly increase the team’s overall chance of success. No matter how direct or slow the buildup the team is making, if a “50/50″ ball happens where your team has no better than a 50% chance of success in retaining possession, your team’s overall chances of success in creating a scoring chance from that possession will be cut in half. If your team’s players can choose to pass or dribble only when they have an 80% chance or better of successfully retaining possession, then overall your team can have a greater chance of success overall even if your team has to dribble and pass more to create the scoring chance.

When you consider teams may only be successful half the time at getting a shot off when in scoring position, and then only about 50% of shots may be on target, and only about 25% of shots on target may score, you can easily see why goals are so rare in soccer. If a team gains possession on a turnover already in scoring position, they still might only have .5 x .5 x .25 or only 6.25% chance of scoring even though they were in an immediate scoring chance. When teams have to move the ball 80 yards (which we have just analyzed at around a 5% chance of success) before they get into a scoring chance that only has around a 6% chance of success, then a team’s chances of taking the ball from the goalie’s hands into the opposing net become .05 x .06 or a microscopic .3%.

Having skilled players that not only consistently choose actions with high percentages of success but have the skills to skew percentages of success in their team’s favor become extremely important in increasing your team’s chances of successfully moving the ball down the field and scoring. When your team chooses higher percentage plays, unsuccessful buildups still are more likely to result in turnovers further down the field, meaning the other team statistically has more to do before they have a scoring chance. On defense, if your players are able to decrease the chances of success the other team has while on offense, statistically, they will cut the other teams scoring chances and are more likely to receive the ball in advanced positions.

A Discussion of the Objectives of a Soccer Team During a Match

Outdoor soccer is played on a large field with many players. Teams win the game by scoring more goals than their opponent, but for a vast majority of many games the ball is out of scoring range for either team as the opposing sides try to advance the soccer ball into scoring positions. Because of the generally long distances that need to be covered by the team in possession of the ball in order to get in position to make a good shot on goal, it is important that each member of the team make good decisions while in possession of the ball or else the team’s possession will end in an all-to-frequent turnover before the team is able to get to the offensive section of the field.

Further complicating the game is the fact that substitutions are extremely limited at competitive levels, making competitive games a true feat of endurance for the 90 minutes of a normal soccer game as it is common for players to run more than 10 kilometers during a game. Teams and their players must manage fatigue while engaged in offensive and defensive tactics throughout the duration of the game. Resting, or minimizing exertion, is most easily done while one’s own team is in possession of the ball in the offensive half or offensive third of the field. Resting on defense is inviting the opposing team to score. Dominating offensive possession also has the added bonus of not allowing the other team to score since they don’t have the ball.

Soccer players will also use possession of the ball the same way a boxer uses the jab and body blow. Taking the ball up and down, back and forth across the field wears the opponent out mentally as well as physically in much the same way as the jab and body blow weaken and fatigue the opponent in the ring. When your opponent on the pitch is weak and tired, they won’t be playing as intensely and a prone to making mistakes that can lead to scoring chances and hopefully goals.

Good soccer is played by players who are constantly evaluating risk vs. reward scenarios in their minds. Before making a 60 yard sprint down the field, diving in on a tackle, or making a pass, players have to make an evaluation that their actions are likely to be successful, and that the consequences of a successful action will be better than the consequences of failure. Even within the range of failed action, players hope to fail in a way that won’t negatively affect their team too much. For example, a player should understand that if they miss a tackle, they could end up still in position to make a play, or completely out of position. Or, if a player is going to miss a pass, it won’t hurt the team as much if you miss wide and down the field compared to missing a pass centrally and close to your own goal. On defense, a player also has to understand which player to mark in fluid, flowing play based on the chances they have to score.

With this in mind, a good soccer player understands accurately the percentage chances of their actions, their team’s actions, and their opponent’s actions. A great soccer player is able to skew those percentages in their favor with their skill — making 60% chances into 80% chances and 80% chances into 90% chances.

Soccer Statistics in a Modern Game

Soccer is a game played for 90 minutes between two teams of eleven people yet traditional soccer statistics of shots, goals, saves, tackles, fouls, and corner kicks only tell the story of a few minutes of each game. The main purpose of this soccer blog is to bring some sort of enlightenment to the other 85 minutes or so of a soccer game. Technologies such as GPS used to track the movements of all players and the ball are just starting to exist at the top professional levels of the game. This level of detail will allow new types of statistical analysis never before seen in the game. Over the coming weeks, months, and years, I hope to provide some fresh thoughts on how we can use this advanced level of detail to better play and understand the game.