**2.2 "Relative Playing Area per Player"and "Number of Players": Physiological responses**

Relative playing area per player should be calculated by dividing the total play surface of each SSG among all players (m2 per player) [25]. Some authors have found that SSGs' intensity can be manipulated by modifying the relative playing area per player and the player numbers. For instance, Hill-Hass et al. [26] examined the effect of three formats of player numbers (2 vs. 2, 4 vs. 4, and 6 vs. 6) with the same relative playing area (150 m<sup>2</sup> per player) on physiological patterns and rate of perceived exertion (RPE). As a relative pitch area per player decreased, the overall physiological performance and RPE increased. In fact, for a fixed pitch area, the lower number of players, the higher the RPE was [19, 23, 26]. As a counterpart, Rampinini et al. [27] performed research with a variety of relative playing areas per player, although the number of players was always equal. Thus, it was clearly shown that in the 3 vs. 3 and 6 vs. 6 formats, increase in pitch size led to higher physiological parameters and perceived intensities (heart rate, blood lactate concentration, and RPE).

Other researchers compared conventional formats (4 vs. 4, 6 vs. 6, 8 vs. 8, from 71 to 106 m2 per player) with 10 vs. 10 small game (311 m2 per player) and competitive matches (1-4-3-3 formation), concluding that only the 10 vs. 10 format allowed players to


#### **Figure 1.**

*SSG formats of 4 vs. 4. SSG1: Non-oriented space. SSG2: Oriented space without goalkeepers and with small goals. SSG3: Oriented space with goalkeepers and official goals (extracted with permission from Casamichana & Castellano [10]). In brackets, the width and length of the pitch used in each design (in meters).*

reach similar intensities and distances to those obtained during matches, whereas the 4 vs. 4 format exhibited the greatest difference in mechanical work and the least difference on distance above 14.4 km/h [28]. Previous studies conclude that increasing the number of players (and concomitantly relative playing area per player) increases total and highspeed distance (>14.4 km/h) during SSGs [29–31]. Owen et al. [32] also reported that these formats do not induce high-speed movements compared with the ones with larger relative playing area per player and therefore more players (9 vs. 9 to 11 vs. 11).

#### **2.3 Floater players during small-sided games**

The *"floater"* is a special player who belongs to the team in possession of the ball during the development of the SSGs, allowing teams to obtain a numerical superiority [33]. The load imposed on regular players when performing SSGs with different numbers and distributions of floaters has been studied in other studies [34, 35]. Sánchez-Sánchez et al. [34] observed that the introduction of interior and exterior floaters reduces the RPE, the heart rate response, and the number of dribbles with respect to the control situation, without the presence of floating players. Regarding floater's performance, Lozano et al. [35] compared 4 vs. 4 + 2 format with 8 vs. 8 + 1 (area: 44–75 m2 per player) and official matches, reporting that total distance, high-intensity distance (>14.4 km/h), sprint distance (>21 km/h), accelerations (>2 m/seg2 ), and decelerations (<sup>&</sup>lt;2 m/seg2 ) were lower in the floaters compared with regular players. In this way, Rábano-Muñoz et al. [36] showed that floaters registered lower external training loads in comparison to regular players with respect to peak velocity and maximum heart rate.

#### **2.4 Technical-tactical outcomes**

Regarding rules inherent to tactical or strategic outcomes, there are studies with special considerations. For example, Fradua et al. [37] extrapolated SSGs'sizes from the actual pitch (11 vs. 11) to investigate parameters related to tactics in the game and concluded that pitch size is a variable that influences ball possession. Thus, the variation in pitch size can create favorable (and unfavorable) conditions for attack and defense [38, 39]. Other authors concluded that SSGs with 9 vs. 9 to 11 vs. 11 (218–336 m2 per player) are also more suitable to simulate most of the specific technical profile (passing actions, such as long-distance and penetrative passes), while 4 vs. 4 format (94 m2 per player) makes more emphasis on more short distance passes during the activity [32]. In addition, Casamichana & Castellano [10] examined physical, physiological, and motor responses and RPE during different SSGs (<sup>75</sup>–275 m2 ) while the number of players per team was kept constant: 5 vs. 5 plus goalkeepers (the participants were 10 male youth soccer players). When the individual playing area was larger, the effective playing time and the physical-physiological patterns were higher, while certain motor behaviors were observed less frequently (interception, control and dribble, control and shoot, clearance, and putting the ball in play). The authors concluded that the size of the pitch should be taken into consideration when planning training drills, as it influences the intensity of the task and the motor response of players.

Furthermore, different functional movement behaviors emerged as a consequence of the manipulation of the environmental situation. For instance, Gonçalves et al. [40] compared the players' positioning dynamics, manipulating the number of opponents and teammates (numerical inequality) during professional and amateur SSGs. The participants played 4 vs. 3, 4 vs. 5 and 4 vs. 7 games (109–171 m2 ), where one team was confronted with low-superiority, low- and high-inferiority situations, and their

*Methodological Approach in the Development of Specific Games in Elite Soccer DOI: http://dx.doi.org/10.5772/intechopen.108399*

opponents with low, medium, and high-cooperation situations. The conclusions revealed that the increasing number of opponents was effective to overemphasize the need to use local information when deciding a position making process in professional players (they presented higher regularity in movement behavior as the number of opponents increased). Conversely, amateur players still rely on external informational feedback (when cooperation was increased, more spatial organization was obtained and players' local perceptions were emphasized).

In this context, *"conventional SSGs"* could facilitate the development of a core tactical concept with an appropriate game context, although this will depend on its design [19]. For our methodology proposal, this new line of analysis leads to another approach in specific soccer games: the *"Possession Games."*

#### **3. The possession games**

Not only are the SSGs' traditional approaches commonly used in the soccer world [9, 20], but other games are also practiced with the main goal of progressing with the possession of the ball by the attacking team. Among them, we can find possession games (POGs), which are relatively similar to *"conventional SSGs,"* yet nonetheless, have a number of different characteristics. During SSGs, the aim of the task is to maintain ball possession, but the disposition of the players is not preset and the occupation of the spaces is not predetermined, while in POGs, the same spaces are intelligently covered [14]. In the latter, the players who maintain possession of the ball are positioned in such a way that the interrelation among them and the space is as efficient as possible, stimulating the development of individual and collective concepts for the understanding of the game (**Figure 2**).

Effectively, the fundamental objective of this type of exercise is to generate free spaces by means of individual and collective movements, which allow the game to

#### **Figure 2.**

*Basic principles of the possession games: a) ball possession by means of individual movements toward collective movements (e.g., deep movements, diagonal movements, etc.), b) passing, depending on the free space and the different movements (e.g., lateral pass looking for width, vertical pass looking to progress, deep pass between lines, etc.), c) ball recovery, which aims to go to the opposing player in possession of the ball, and finally, d) intercepting and thus preventing the opponent from progressing in the attack, Vilamitjana et al. [41].*

"progress" with greater fluidity in a particular direction (**Figure 2**). This means that the creation of movements to generate free spaces will be useful to make passes toward the mentioned spaces in order to generate collective movements. In relation to this concept, in his book *"Me gusta el Fútbol"* [41], Johan Cruyff synthesizes the game of soccer with this following phrase: *"Don't run too much since soccer is played with the brain. You have to be in the right place at the right time, not before or after."* This principle gives rise to factors inherent to strategy and tactics, which have a greater transfer toward specific match situations [14]. In this line, the practice of POGs will be most effective in pitches designed with different shapes and spaces (**Figure 3**).

#### **Figure 3.**

*POG designs for the three formats (6 vs. 6, 7 vs. 7 and 8 vs. 8) studied by Vilamitjana et al. [14]. In brackets, the width and length of the pitch used in each design (in meters).*
