Friday, March 14, 2008

Cutting-Edge Research: Players Adjust Their Style of Play Artificial Turf

The introduction of the new artificial turf fields has raised a number of important questions. In an earlier article, safety issues and injury risk potential was discussed (see “Safety of Artificial Turf Fields, November 2007). Coaches and players have also debated the performance aspects on playing on artificial turf. They often describe matches on turf as being “faster”, requiring more technical skill and more physically demanding. In the January 2008 issue of the Journal of Sports Sciences, Helena Andersson and colleagues of Örebro University (Sweden) published a study that examined the movements patters, technical skills and perception of players playing matches on artificial turf and natural grass. Their results suggest that players adapt their style of play based on the type of surface being played on.


The investigators examined male and female players in the top Swedish leagues during matches played on natural grass and artificial turf. In the first part of the study, player movement patterns and technical abilities during competitive matches were recorded. Computerized analyses measured the distance covered during the match, the number of sprints, percentage of time running and standing, etc. They also analyzed skills and technique, such as the number of passes attempted and completed, shots taken, and so forth. In the second part of the study, players were asked to rate their perceptions of playing on artificial turf versus natural grass. They were asked if playing on turf is more physically demanding, tougher to complete passes, or harder to make runs with the ball.

The results of match play were interesting. During matches, players showed similar movement patterns on both surfaces. They covered slightly more than six miles and spent roughly the same amount of time standing, walking, jogging and sprinting. This was the case early minutes of the match as well as near the end, when the effects of fatigue would be most obvious.

As for technical skills, two key differences emerged. First, the investigators found that players executed twice as many slide tackles on grass as they did on turf. Second, the investigators found that players attempted and completed more passes when playing on turf. Specifically, there were 30% more short passes played within the midfield zone. There were no differences in the number of long passes executed. Based on these findings, it appears that when playing on turf, the players adopt less aggressive form of defending. They also adopt a more possession oriented style of play. Players tend to hold onto the ball in the midfield zone rather than playing through to the offensive end. It may be that the less aggressive style of defending makes it easier to maintain possession in the midfield zone. It is also possible that improved ball control on turf make this an easier form of play.

The researchers also found that, for the most part, players had a negative perception of playing on turf. They felt that is was more physically demanding and more difficult to execute passes, to control the ball and to take a shot. This is interesting since the amount of standing, jogging and sprinting were nearly identical on each surface and more successful passing was executed on turf. The discrepancies between perception and execution are difficult to reconcile. It is possible that the physical demands are, in fact, greater on turf but that players are able to overcome them so that their intensity of play does not suffer. It is possible that the player’s perceptions about playing on artificial turf are formed prior to playing. That is, players have a preconceived notion that “playing on plastic” is taxing and difficult. This is one question that needs to be reconciled, is playing matches on turf more demanding that playing on grass?

This study may have implications for teams that routinely train on artificial turf. Does the style play on turf observed in this study (more possession, less aggressive defending) also occur during training? If it does, do teams that train exclusively on turf develop a different style of play than teams who train on grass? Does training on turf help or hinder the technical and/or tactical development of individual players? The answers to these questions are unknown but coaches should be aware that training on turf, my causes players to alter their tactical approach to the game.

Based on the work of Andersson and colleges, it appears that teams and players make adjustments in their style of play when playing matches on artificial turf. This results in a more possession and ball control in the middle of the field and a less aggressive style of defending. Players also report that they feel that turf is more physically demanding than grass. Coaches should be aware of the differences in play and perception and should consider adjustments to both matches and training sessions.

Reference:

Andersson H, Ekblom B, Krustruo P (2007) Elite football on artificial turf versus natural grass: Movement patterns, technical standards, and player impressions. J Sports Sci, 26:113-122.