Referees add more extra time when the big teams are losing

Football (soccer) enthusiasts suspected it, but now statistics is confirming it. After analysing all the matches of the Spanish league "La Liga" from the 2014-2015 season, two experts in sports science have found that the greater the difference on the scoreboard, the less stoppage time is added to the end of the game. When the score is tighter, however, referees tend to add more stoppage time when the team in the higher division is losing.

The stoppage time added by the referee following the obligatory 90 minutes of a football match is used to compensate for time lost due to substitutions, injuries, expulsions and other incidents that arise during the game, but it seems as though other factors also play a role according to a new study.
Researchers Carlos Lago, from the University of Vigo (Spain), and Maite Gómez, from the European University of Madrid, have confirmed that referees favour the big teams by reducing the extra time when these teams are ahead on the scoreboard. In contrast, and according to an article published in the journal 'Perceptual and motor skills', referees slightly draw out the match when the big teams are losing.
To carry out the study the authors relied on data from the 380 matches played in the Spanish league during the 2014-2015 season. They then took several variables into account -such as the difference in goals on the scoreboard, the playing level of each team, the number of red and yellow cards, player substitutions, the average number of assists and fouls committed- to see if any of them had an influence on the amount of stoppage time.
After applying a statistical method (called linear regression and widely used to identify relationships between variables), it was observed that the greater the difference on the scoreboard, the less stoppage time was given by the referee. In very tight matches, nevertheless, refs tend to add more seconds when the team in the higher division is losing, and fewer seconds when they are winning. The number of red cards and fouls also cause an increase in extra time.
"The typical complaint from less powerful teams regarding how referees treat big teams better might make sense," explains Carlos Lago, "as their decisions tend to benefit the higher‑ranked teams when the scoreboard is against them. Furthermore, the more important the difference between the clubs, the greater the advantage." As the inequality between the teams decreases, because either two big teams or two small teams are playing against each other, this statistical trend disappears.
A bias that also favours local teams
Previous studies had already demonstrated that pressure from local fans also has an influence on referees when it comes to adding on more or less time. In the Spanish league, specifically, referees add 112 more seconds when the home team is losing by one goal or winning with a minimal difference.
This bias in favour of local teams was also found at football matches of the Bundesliga (Germany), Serie A (Italy), Premier League (United Kingdom), Major League Soccer (USA and Canada) and of the Campeonato Brasileiro (Brazil) leagues.
According to Lago, "what is most troubling is that the partiality of some referees for local teams and big clubs seems to have a name and surname, meaning that refs with less experience are more affected by the noise around them; there are also referees who are more or less home-biased and show a greater or lesser tendency to benefit the big teams in specific situations."
The expert in sports science concludes with some recommendations: "improve referee training and prevent subjectivity in their decisions to the extent possible, which at present have not proven to be malicious, but simply human. Additionally, technology could also help, although referee bias can decrease if they are simply aware of the role they play in the outcome of the matches."

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Wearable neuromuscular device may help reduce ACL injuries in female soccer players

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Using a wearable neuromuscular device can reduce the risk of ACL injury in female soccer athletes, according to new research presented today at the American Orthopaedic Society for Sports Medicine's (AOSSM) Annual Meeting in Colorado Springs, CO. The study showed functional improvements in athletes who used the devices in combination with a regular training program.

"Our study showed that training with a wearable neuromuscular (WNM) device improved postural control in athletes, without limiting performance," said Michael John Decker, PhD, from the University of Denver in Denver, Colorado. "Moreover, no athletes in the study experienced an ACL injury during training or over the course of the following season." 

A total of 79 elite youth and collegiate female soccer players (age 12-25) in the study trained with a WNM device that applied bi-lateral, topical pressure to the medial quadriceps and hamstring muscles. The athletes performed 7 to 9 weeks of pre-season training with the device consisting of strength and conditioning exercises and on-field team practices. 

"Research has shown female soccer players have a three times greater risk of ACL injury compared to males, yet only a small portion of soccer coaches are currently utilizing ACL injury risk reduction programs," commented Decker. "We hope these devices offer coaches a practical means to overcome participation barriers, opening the door for more organizations and teams to implement similar programs."

Mental training for soccer tactics

It's not only controlling the ball, physical endurance, and dexterity that matter when it comes to playing soccer. Members of a soccer team also have to be at the top of their game when it comes to tactical strategy. Researchers at the Cluster of Excellence Cognitive Interaction Technology (CITEC) at Bielefeld University have developed a mental training technique that helps soccer players improve their tactical action. The "kicker" here is that the players can practice with this method without actually being on the playing field.
"In soccer, as in other team sports, all players on the team have to work together harmoniously -- especially when it comes to tactical action," says Professor Dr. Thomas Schack. The sports scientist and cognitive psychologist specializes in recording how athletes store and recall sequences of action for a game in their memories. He heads the research group "Neurocognition and Action -- Biomechanics" and works at the Cluster of Excellence CITEC. "These days, there is hardly any difference in the physical fitness among soccer players of the same performance class. For this reason, the mental conception of tactical team action can be a decisive advantage." A tactically experienced team can successfully conceal their real plans from their opponents. This can help them outwit their competitors and determine the very outcome of the game. "The problem is that for many players, tactical team action is stored incorrectly -- or not at all -- in their memory. We have developed a technique that allows athletes to (re)learn this missing knowledge," explains Schack.
The new method draws upon the athlete's mental powers of imagination, and was tested with athletes who play futsal, a version of indoor soccer where the ball is passed significantly faster than in standard soccer played on a grass field. In futsal, two teams, each with five players, score by shooting into handball goalposts.
"Our technique is based on photographs and textual explanations of typical tactical situations," says Dr. Cornelia Frank, a member of Schack's research group. These photos and textual descriptions allow the players to mentally put themselves in the situation of the game, and imagine their teamwork up to and including successfully scoring a goal. The sports scientist calls the new technique "Joint Action Imagery." Dr. Frank and student Gian-Luca Linstromberg have applied and analyzed the method for the first time in a study on participants from a Bielefeld University sports group.
The test subjects were shown a photo with a scene of a tactic being played out, such as a counterattack. They were told to put themselves in the place of a certain player in the picture. As part of this mental positioning, they received an explanation of how the tactical maneuver unfolds from player's point of view, e.g.: "You intercept the ball on the right side of the field. In front of you is a member of the opposing team, and to the left and right are two players from your team. You speed up, and then pass the ball to the teammate on your right." Next, the test person was told to vividly imagine the situation ten times in a row. This mental training was practiced for four weeks, along with regular sports training at the gym. Players were led through the mental exercise twice a week, and once a week players went through the training using a script on their own at home.
Futsal players of average experience took part in the study, and a total of 12 players went through the mental training. At both the beginning and end of the study, the researchers measured how well the test subjects mentally internalized the four tactics -- playmaking, counterattack, shifting to defense, and pressing. To evaluate this, the test subjects had to make tactical decisions for different game situations. They were shown two different situations at a time and then had to judge whether the same tactic can be used to react to both cases.
"The main finding here is that the mental training enabled the players to better distinguish between the various tactics than before," says Cornelia Frank. The progress made by the test subjects was compared with a control group of futsal players, who had not participated in the mental training. "The astonishing thing in comparison to the control group was that the players that had practiced the mental training developed functional, that is, proper mental conceptions of the tactics. With this, their mental tactical skills moved towards that of professional players."
Cornelia Frank will present the new training technique at the end of July during the sports symposium of the Deutschen Vereinigung für Sportwissenschaft (German Association of Sports Sciences, dvs). The symposium will be held together with the conference "Teaching Games for Understanding." In her conference presentation, Dr. Frank will also go into greater detail on which effects of the mental training should be subject to further research: at this point, it is still unclear whether such training helps players actually make suitable tactical decisions on the playing field. It also remains to be seen whether the training helps players better understand the tactical instructions given by their coach, or makes them better able to discuss these tactics with the coach and fellow teammates. One thing, however, is clear: "With our method, players learn the basics of soccer strategy, which every coach requires, in a short amount of time. And the players get a better understanding of which tactical approach can be called upon for different situations."

Goalkeepers prone to 'gambler's fallacy' but penalty takers fail to exploit it

After a string of penalties aimed in the same direction, goalkeepers are more likely to dive in the opposite direction on the next penalty

After a string of penalties aimed in the same direction, goalkeepers are more likely to dive in the opposite direction on the next penalty but kickers fail to exploit this pattern, finds new UCL research.
The study, published in Current Biology, shows that penalty shoot-outs in international tournaments resemble a psychological game. The researchers studied penalty shoot-out videos from all World Cup and Euro finals tournaments between 1976 and 2012.
They found that each team of kickers produced more or less random sequences of kicks to the left or the right of the goal. Goalkeepers' dives to the left or the right were not related to the direction of the kick, suggesting that goalkeepers at this elite level make their decisions in advance, rather than reacting to each kick. However, goalkeepers' decisions were non-random in one crucial respect: when the kickers repeatedly kicked in the same direction on consecutive penalties, goalkeepers became more likely to dive in the opposite direction on the next penalty. The goalkeepers therefore display what has been called the 'gambler's fallacy' – like a person who believes that after coin flips produce a run of 'heads', the next flip is bound to produce 'tails'.
"Complete randomness is generally the best strategy in competitive games" says lead author Erman Misirlisoy of the UCL Institute of Cognitive Neuroscience. "Because the goalkeeper displays the gambler's fallacy, kickers could predict which way the goalkeeper is likely to dive on the next kick. That would obviously give the kicker an advantage – they would simply aim for the opposite side of the goal. Surprisingly, though, we found that kickers failed to exploit this advantage".
"Often you can only win in elite sport by exploiting tiny weaknesses in your opponent's strategy", explains senior author Professor Patrick Haggard. "We can only speculate on why goalkeepers can get away with non-randomness, without the kickers exploiting it. One possibility is that penalty shoot-outs are relatively rare. But there is a more psychologically interesting possibility: shoot-outs are asymmetric, because one goalkeeper faces several different kickers, one after the other. Kickers are under enormous pressure, focussed on the moment of their own kick. Each individual kicker may not pay enough attention to the sequence of preceding kicks to predict what the goalkeeper will do next."
Erman Misirlisoy adds: "People can learn to predict: perhaps football coaches could study the gambler's fallacy, and could train their penalty kickers in preparation for the next World Cup. At the same time, goalkeepers could also learn to be less predictable".

Physics experts: Soccer ball created for the 2014 FIFA World Cup is a “keepers’ ball”.

New Ball to Showcase Talent in World CupUniversity of Adelaide

The new ball, called Brazuca, should be much more predictable than the 2010 World Cup ball, Jabulani, which was less-than-affectionately labelled a ‘beach ball’ because of its sometimes erratic flight path.
“The Brazuca has very deep grooves – it’s much rougher than Jabulani – and this creates a different pattern of air flow around the ball,” says Professor Derek Leinweber, Professor of Physics in the University’s School of Chemistry and Physics. He has previously written about and lectured on the aerodynamics of cricket balls, golf balls and earlier World Cup soccer balls.
“The Jabulani was much smoother than the Brazuca with smaller grooves and ridges across its surface,” says Professor Leinweber. “That meant the ball had to be moving much faster before the airflow around the ball changed from smooth to turbulent. As this shift to turbulent airflow occurred at high speeds, the ball could make some pretty erratic movements on the way to the net.
“In contrast the Brazuca, with its deeper grooves, hits that turbulent air flow at a lower speed with the result that the ball is much more predictable. In many ways, it’s a return to the aerodynamics of the old 32-panel ball.”
Professor Leinweber and PhD candidate Adrian Kiratidis have been investigating the likely performance of the new ball by matching up the physics of air flow with available wind tunnel data and video of the ball’s movement.
Mr Kiratidis says he believes players taking hard and fast shots in this World Cup won’t find the Brazuca as easy to bend into the net as they did with the Jabulani.
“Keepers facing players of the calibre of Messi, Cristiano Ronaldo or Neymar are going to be glad that it’s Brazuca coming at them rather than Jabulani,” he says.
Mr Kiratidis will explain the science behind World Cup soccer balls at a free public lecture on Thursday 12 June at 6.30pm, just hours before the first kick-off in Brazil.
The lecture, The Brazuca – a better ball?, will be held at 6.30-7.30pm, Lecture Theatre 102, Napier Building, at the University’s North Terrace campus.
Commentary from Professor Leinweber and Adrian Kiratidis on the Brazuca is available on the YouTube video at https://www.youtube.com/watch?v=ohwJgkbbuqs.

Female soccer players get tired more, run hard less

 

Every year billions of people across the globe tune in to watch the UEFA Champions League in which men compete, yet the number who tune-in to watch the female equivalent is miniscule and research carried out at a North East University has discovered it is a whole different ball game.

For the first time both versions of the sport have been compared by the University of Sunderland to discover how the male game differs from that of the female game from a physical and technical point of view.

Research published in the journal Human Movement Science analysed 54 male and 59 female football (soccer) player observations in the UEFA Champions League. It is the first study to focus on high-intensity running in football for both men and women.

They found that during the course of a typical UEFA Champions League match male players covered approximately 3-5 per cent more distance in total than females but covered around 30 per cent more distance at high intensity. The research also showed female players did not cover as much distance in the second half at a high intensity as they did in the first half, while male players did manage to maintain their running performances.

There were no gender differences shown between attackers and central defenders; however male full-backs, central and wide midfielders covered more distance at high intensity compared to female players in the same position.

The research, 'Gender differences in match performance characteristics of soccer players', also showed the difference in technical characteristics with female players losing the ball more frequently and having a lower pass completion rate.

Dr Paul Bradley, led the research and is a Senior Lecturer in Sport and Exercise Science at the University of Sunderland. He said: "We can clearly see that the male and female game at the top level is very different both physically and technically. It was very interesting to see fairly similar total distances but substantial differences at high intensity between gender. The larger drop off in running performance in the second half for females could be due and their lower physical capacity thus, the demands of the game cause fatigue in the second half."

It is now hoped the research can be used to provide gender-specific training for professionals in both male and female footballers to improve physical and technical performance.

MLB pitchers don't regain performance level after Tommy John surgery

     Major League Baseball players who undergo Tommy John surgery are less likely to regain the performance level they had before surgery, according to a Henry Ford Hospital study.

The study is the first to show a link between the surgery and declining pitching performance at the professional level. It also involved the largest cohort of professional pitchers to date to examine the issue.

Researchers analyzed pitching statistics of 168 MLB pitchers before and after surgery between 1982 and 2010 and found diminishing returns in three major pitching categories: Earned runs average (ERA), walks and hits per inning pitched (WHIP) and innings pitched (IP). The findings:

ERA increased 4.15 to 4.74.
WHIP increased 1.40 to 1.48.
IP declined 59 to 50.

"Tommy John surgery is an effective surgery and most pitchers get back to pitching after surgery. But it's not going to improve their level of performance," says Vasilios (Bill) Moutzouros, M.D., a Henry Ford orthopedic surgeon and the study's senior author.

"There's been a perception that the surgery will make you better. Our findings debunk that perception. Eighty to 90 percent of major league pitchers will get back to pitching at the major league level but they just won't be as effective as they were before injury."

The study is being presented at the annual meeting of the American Academy of Orthopedic Surgeons March 11-15 in New Orleans.

Tommy John surgery, named after the former Los Angeles Dodgers pitcher who underwent the pioneering surgery 40 years ago, has been since performed on legions of pitchers at the professional and collegiate levels. In medicine it is known as ulnar collateral ligament (UCL) reconstruction. During the two-hour outpatient procedure, the ulnar collateral ligament in the medial elbow is replaced with a tendon from the same arm or from the hamstring area.


               
       

 IMAGE: This is Vasilios (Bill) Moutzouros, M.D., a Henry Ford Hospital orthopedic surgeon and study's senior author.
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Until Henry Ford's observational study, other research had shown that a high percentage of players returned to the same level of performance after UCL reconstruction, and the perception among players, coaches and parents was that UCL reconstruction would even lead to a higher level of performance. In the only other study involving just MLB pitchers (68 pitchers), 82 percent of them returned to the mound after surgery and had no significant decline in performance.

Henry Ford researchers sought to examine the effects of UCL reconstruction on pitching performance involving the largest cohort of MLB pitchers and identify risk factors associated with the pitching injury, says Robert Keller, M.D., a third-year Henry Ford orthopedic resident and study co-author whose father Phil was a teammate of Tommy John in the 1970s.

The cohort of 168 pitchers pitched in at least major league game after undergoing UCL reconstruction between 1982 and 2010. Data collected included the year of surgery, pitchers' age, years of MLB experience, height/weight, body mass index, pitching arm injured, pitching role, pitching statistics, and whether the pitcher returned to MLB pitching after surgery. This was then averaged for the three years of pitching before UCL reconstruction and for the three years after returning to play.

For comparison, researchers collected similar data of 178 MLB pitchers in a control group with no prior UCL reconstruction and age-matched them with a corresponding UCL reconstruction pitcher. Performance was determined using three years of statistics before their "index year" (their roster year of either 2004 or 2005) and three years after their "index year."

Drs. Moutzouros and Keller used paired analysis, generalized estimating equation model and other commonly used research tests to evaluate the data. Other highlights:

- UCL pitchers were "statistically better" than the control group in ERA, WHIP, IP and win percentage in the three years and two years before surgery.
- In the year before surgery, UCL pitchers' performance declined significantly.
- After surgery, the control group was either superior in nearly every performance measure or no difference observed.
- A predictor of surgery is MLB experience. Sixty percent of pitchers required UCL reconstruction within their first five years in the MLB.
- While the cause of UCL injury is not fully known, orthopedic specialists theorize it's due to overuse and stress on the elbow, pitching velocity and joint motion, Dr. Keller says, adding that surgery isn't a panacea.

"We even have parents who come into our clinic asking if their children can have the surgery even before they injure anything because they think potentially it can make them better. What this study shows is it doesn't. Matter of fact, players get statistically worse after having this surgery."