Tactics and Science Behind the Substitutions in Football

One of the most basic and important features of team sports is the right to change players. While this right is unlimited in sports such as basketball, volleyball and handball, there is a certain limit to it in football.

In this context, coaches should pay attention to many factors during the game while changing the player. These factors, which vary according to the tactical planning determined according to the flow of the game and the characteristics of the player at that time, can contribute to the team when applied correctly.

Why do the players that many football fans want to see in the starting 11 in their teams start the match on the bench?

How do substitutions change the fate of the game? We will try to examine this in this article.

Although further research is needed on this subject, we will seek answers to these questions with professional observations together with the research that has already been done.

Football is a game that includes prolonged physical activities. In this context, it is important that the players have the energy to do these activities during the match.

A player cannot be expected to be as energetic as at the beginning of the match for 90 minutes without extra times added. It was proven in certain studies that the physical performance of the players in all positions decreased in the second half, but it was observed that the effort of the players in certain positions was higher according to the tactical understanding of the team and certain variables such as the time the ball was in play.

These players cannot give the team as much efficiency in the remaining parts of the match as in the first half. In the meantime, the right to make substitution comes into play and the coach changes the tired player to gain dynamism to the game.

According to researches, the changes made in the second half not only reduce the tempo reduction of the team but also increase the average high-intensity activity done by the players.

The basic question here is whether the player who replaces the tired player is only the best player on the bench, or is this player chosen according to the physiological, physical and mental characteristics of the player when entering the game?

In fact, the answer to this question depends on the situation of the game and the goal of the team at that time. It is expected that while the team, whose aim is to maintain the score, receive a defensive player who has high aerobic endurance and can provide the necessary support to the team’s defence in the second half, the team whose aim is to get ahead is expected to receive a player with more anaerobic characteristics that may cause danger to the opposing team.

So, what does the research on this subject say? First, we will look at the factors that cause fatigue in football players during a match.

PHYSIOLOGICAL FACTORS THAT CAUSE FATIGUE DURING A MATCH

It would not be correct to generalize the substitutions made during the game, but research shows that the substitutions are generally between 60th and 80th minutes.

If we assume that the players rest for a minimum of 15 minutes after the end of the first half, we can assume that they have accumulated enough energy to increase the first 15 to 20 minutes in the second half, but then there may be a serious decrease in glycogen stores.

This reduction affects players’ capability of doing repeated sprints and high intensity running. Studies have proven that glycogen levels drop between 37% and 90% during the competition.

This means that individual muscle fibres are depleted seriously. One of the factors that have effects on fatigue is thought to be the inadequate filling of creatine phosphate stores due to repetitive sprint activities during the match.

Although this factor is not as serious as the depletion of glycogen stores, it seriously reduces the performance of football players who do explosive sprints during the match.

Studies on this subject have shown that; CP levels drop to 60%, especially when the player goes into a resting phase after a high-intensity activity in a football match.

If the number of repetitive high-intensity sprint is high, this rate decreases to 30%. This means a serious decrease in storages. These are factors that must be taken into account when preparing a club for matches, both tactical and physical.

With a simple example, if the player, whose ability to make explosive sprints dominates, enters the game after 70, both gain dynamism to his own team and causes the already tired defence of the opposing team to defend more difficult.

The best real-life example we can give to this is the friendly match played between Spain and Portugal on October 7, 2020. With Adama Traore, one of the players with the highest explosive power, entered the game in the 62nd minute, the Spanish national team gained dynamism and Traore had significantly forced the Portuguese defenders with his sprints.

This example shows that when making changes, the physiological character of the actor is as important as his or her technical capacity.

SUBSTITUTIONS ACCORDING TO POSITIONS

We’ve reviewed the average minutes that substitutions are made. So, according to the studies which positions are substituted more in the game?

In our Workload Management in Football article, we saw which positions make more high intensity running. If we want to remind briefly, positions that make the highest intensity running to lowest as follows:

• Forwards
• Wide Midfielders
• Central Attacking Midfielders
• Central Defensive Midfielders
• Full Backs
• Stoppers

Research dealing with substitutions in positions during the match supports the list above. In this context, the positions where the most replacements are made during the match are respectively attackers, wide and central midfielders and after these positions, fullbacks and central defenders.

EFFECT OF SUBSTITUTIONS ON MATCH

Above, we examined the positions that were fatigued fastest and subsequently changed. In this part of our article, we will examine the effects of these changes on the physical activities of the team during the match.

It was observed that the players entering the game covered more distance than the players who replaced and completed the entire game, as well as doing more physical activities such as jogging, low intensity running, high intensity running and sprinting.

There was no difference between the players who were taken out from the game and the players who entered, especially in activities such as the pass completion rate.

It has been observed that the central and wide midfielders, who are involved in the game in the second half, have covered more distance during their time in the game in this period.

It was determined that the offensive players entered the game in the second half performed more high-intensity running activity during this period. You can find one of the most important academic articles on this subject below:

Bradley, P. S., Lago-Peñas, C., & Rey, E. (2014). Evaluation of the Match Performances of Substitution Players in Elite Soccer. International Journal of Sports Physiology and Performance, 9(3), 415-424. doi:10.1123/ijspp.2013-0304

As I mentioned in the introduction, further research is needed to be more precise about this topic. This article has been written based on personal observations and researches in the literature.