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With the help of a simple model, we show that the hindsight bias can lead to inefficient delegation decisions. This prediction is tested experimentally. In an online experiment that was conducted during the FIFA World Cup 2010, participants were asked to predict a number of outcomes of the ongoing World Cup and had to recall their assessments after the outcomes had been realized. Their answers were used to construct individual measures of the hindsight bias. The participants also had to make choices in a delegation game. Our data confirm that hindsight-biased subjects more frequently fail to delegate optimally than subjects whom we have classified as not hindsight biased. Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2014.2087. Keywords: hindsight bias; delegation; experiments History. Received February 13, 2013; accepted August 24, 2014, by Teck-Hua Ho, judgment and decision making. Published online in Articles in Advance March 26, 2015., 1. Introduction There is ample evidence that people fail to remember their past beliefs correctly. After having received new information affecting these beliefs, people tend to exaggerate the availability of [...]

This study investigates the efficacy of intermediate penalty kickers by comparing the effect of applying an automated WiFi system on the field of play to simulate a strategy that takes account of goalkeeper action (dependent) with another for which goalkeeper strategy is irrelevant (independent). Intermediate penalty kickers (n = 12) took a pretreatment test of 32 kicks in a 'real-play' situation with intermediate goalkeepers (n = 3). Two groups of kickers underwent 11 treatment sessions using different strategies and then were administered a posttreatment test. The variables measured were the number of goals scored, whether the direction of the shot was the same or different from the direction of the goalkeeper's move (DDG), ball speed, and the duration of the kicking movement. Data suggested the goalkeepers had a greater capacity to identify advance cues when faced with independent strategy kickers and that dependent strategy kickers achieved lower ball speeds. DOI 10.2466/05.23.24.27.PMS.111.6.947-962

The effect of explicitly providing goalkeeper's movement advanced cue to the kicker during a real penalty kick task was assessed. 32 expert soccer players (M age=23.2 yr.), who were divided into four groups: an experimental group, a discovery group, a placebo group, and a control group, participated. Rate of success in the task was assessed, as well as goals, decision times, and ball flight times. Providing an advance cue significantly improved the players' rate of success relative to players without the advance cue; this difference was still present after I and 7 days without training. The experimental group adapted better to the time range within which the response could be effective, while the discovery group showed adaptations. Explicit instructions about the advance cues available from goalkeepers' actions before the dive during practice can improve penalty kick performance. DOI 10.2466/05.24.25.PMS.111.6.749-760

Castagna, C, Manzi, V, Impellizzeri, F, Weston, M, and Barbero Alvarez, JC. Relationship between endurance field tests and match performance in young soccer players. J Strength Cond Res 24(12): 3227-3233, 2010--The purpose of this study was to examine the relationship between popular endurance field tests and physical match performance in elite male youth soccer players. Eighteen young male soccer players (age 14.4 [+ or -] 0.1 years, height 1.67 [+ or -] 4.8 cm, body mass 53.6 [+ or -] 1.8 kg) were randomly chosen among a population of elite-level soccer players. Players were observed during international championship games of the corresponding age categories and randomly submitted to the level 1 of the Yo-Yo intermittent recovery test (Yo-Yo IR1), the Multistage Fitness Test (MSFT), and the Hoff test on separate occasions. Physical and physiological match demands were assessed using Global Positioning System technology and short-range telemetry (GPS Elite, Canberra, Australia), respectively. Players covered 6,087 [+ or -] 582 m (5,098-7,019 m) of which 15% (930 [+ or -] 362 m; 442-1,513) were performed as a high-intensity activity. During the first and second halves, players attained 86.8 [+ or -] 6.5 and 85.8 [+ or -] 5.8% of maximum heart rate (HRmax; p = 0.17) with peak HRs of 100 [+ or -] 2 and 99.4 [+ or -] 3.2% of HRmax, respectively. Players' Yo-Yo IR1 and MSFT performance were significantly related (r = 0.62-0.76) to a number of match physical activities. However, the Hoff test was only significantly related with sprint distance (r = 0.70, p = 0.04). The Yo-Yo IR1 showed a very large association with MSFT performance (r = 0.89, p < 0.0001). The results of this study showed that the Yo-Yo IR1 and MSFT may be regarded as valuable tests to assess match fitness and subsequently guide training prescription in youth soccer players. The very strong relationship between Yo-Yo IR1 and MSFT suggests their use according to the period of the season and the aerobic fitness level of the players. Because of the association of the Yo-Yo IR1 and MSFT with match physical performances, these tests should be considered in talent selection and development of players. KEY WORDS association football, fitness assessment, match analysis, team sports, intermittent exercise

McCurdy, KW, Walker, JL, Langford, GA, Kutz, MR, Guerrero, JM, and McMillan, J. The relationship between kinematic determinants of jump and sprint performance in Division I women soccer players. J Strength Cond Res 24(12): 3200-3208, 2010--The purpose of this study was to determine the relationship between measures of unilateral and bilateral jumping performance and 10- and 25-m sprint performance. Fifteen division I women soccer players (height 165 [+ or -] 2.44 cm, mass 61.65 [+ or -] 7.7 kg, age 20.19 [+ or -] 0.91 years) volunteered to participate in this study. The subjects completed a 10- and 25-m sprint test. The following jump kinematic variables were measured using accelerometry: sprint rime, step length, step frequency, jump height and distance, contact time, concentric contact time, and flight time (Inform Sport Training Systems, Victoria, BC, Canada). The following jumps were completed in random order: bilateral countermovement vertical jump, bilateral countermovement horizontal jump, bilateral 40-cm drop vertical jump, bilateral 40-cm drop horizontal jump, unilateral countermovement vertical jump (UCV), unilateral countermovement horizontal jump, unilateral 20-cm drop vertical jump (UDV), and unilateral 20-cm drop horizontal jump (UDH). The trial with the best jump height or distance, reactive strength (jump height or distance/total contact time), anal flight time to concentric contact time ratio (FT/CCT) was recorded to analyze the relationship between jump kinematics and sprint performance. None of the bilateral jump kinematics significantly correlated with 10- and 25-m sprint time, step length, or step frequency. Right-leg jump height (r = -0.71, p = 0.006, SEE = 0.152 seconds), FT/CCT (r = -0.58, p = 0.04, SEE = 0.176 seconds), and combined right and left-leg jump height (r = -0.61) were significantly correlated with the 25-m sprint time during the UCV. Right-leg FT/CCT was also significantly related to 25-m step length (r = 0.68, p = 0.03, SEE = 0.06 m) during the UDV. The combined right and left leg jump distance to standing height ratio during the UDH significantly correlated (r = -0.58) with 10-m sprint time. In comparison to bilateral jumps, unilateral jumps produced a stronger relationship with sprint performance. KEY WORDS reactive strength, vertical jump, horizontal jump, unilateral jump, bilateral jump

Dellal, A, Keller, D, Carling, C, Chaouachi, A, Wong, DP, and Chamari, K. Physiologic effects of directional changes in intermittent exercise in soccer players. J Strength Cond Res 24(12): 3219-3226, 2010--The aim of the present study was to compare the physiologic impact of intermittent exercise in specific shuttle running (IS), which requires 180 [degrees] directional changes, and traditional in-line (IL) running. Ten elite male adult soccer players performed different intermittent exercises according to their maximal aerobic velocity (v[??][O.sub.2]max): 30-30 seconds at 100% (30 s of runs at 100% of v[??][O.sub.2]max alternated with 30-s recovery period), 105%, and 110% of v[??][O.sub.2]max with active recovery, 15-15 seconds at 105%, 110%, and 115% of v[??][O.sub.2]max, and 10-10 seconds at 110%, 115%, and 120% of v[??][O.sub.2]max with passive recovery. Each exercise was performed in the IL and IS format in a randomized order. Heart rate (HR) expressed in percentage of HR reserve (HRres), postexercise blood lactate concentration [La], and ratings of perceived exertion (RPE) were recorded. The different 30-30 seconds showed significantly higher HRres responses in IS compared with IL (p < 0.01 ). The [La] and RPE results indicated higher values in IS. In conclusion, the physiologic impact of specific IS is substantially higher than in traditional IL. The changes of direction induce an increase in the anaerobic metabolism solicitation and consequently create different responses compared with traditional IL running. This information can aid coaches in the design of intermittent training programs using classical (IL) or a specific form (IS) of running to induce different physiologic responses. KEY WORDS intermittent exercise, football, fitness training, anaerobic metabolism, 180 [degrees], turning

Williams, JD, Abt, G, and Kilding, AE. Ball-sport endurance and sprint test ([BEAST.sub.90]): validity and reliability of a 90-minute soccer performance test. J Strength Cond Res 24(12): 3209-3218, 2010--The aim of this study was to determine the validity and reliability of a 90-minute soccer performance test: Ballsport Endurance and Sprint Test ([BEAST.sub.90]). Fifteen healthy male amateur soccer players participated and attended 5 testing sessions over a 10-day period to perform physiologic and soccer-specific assessments. This included familiarization sessions and 2 full trials of the [BEAST.sub.90], separated by 7 days. The total 90-minute distance, mean percent peak heart rate ([HR.sub.peak]), and estimated percent peak oxygen uptake of the [BEAST.sub.90] were 8,097 [+ or -] 458 m, 85 [+ or -] 5% and 82 [+ or -] 14%, respectively. Measures obtained from trial 1 and trial 2 were not significantly different (p > 0.05). Reliability of measures over 90 minutes ranged from 0.9-25.5% (% typical error). The [BEAST.sub.90] protocol replicated soccer match play in terms of time, movement patterns, physical demands (volume and intensity), distances, and mean and [HR.sub.peak] values, as well as having an aerobic Ioad similar to that observed during a soccer match. Reproducibility of key physical measures during the [BEAST.sub.90] were mostly high, suggesting good reliability. The [BEAST.sub.90] could be used in studies that wish to determine the effects of training or nutritional interventions on prolonged intermittent physical performance. KEY WORDS football, soccer protocol, intermittent

To compare the effects of explosive strength (ExpS) vs. repeated shuttle sprint (RS) training on repeated sprint ability (RSA) in young elite soccer players, 15 elite male adolescents (14.5 [+ or -] 0.5 years) performed, in addition to their soccer training program, RS (n = 7) or ExpS (n = 8) training once a week for a total of 10 weeks. RS training consisted of 2-3 sets of 5-6 x 15-to 20-m repeated shuttle sprints interspersed with 14 seconds of passive or 23 seconds of active recovery ([approximately equal to] 2 m x [s.sup.-1]); ExpS training consisted of 4-6 series of 4-6 exercises (e.g., maximal unilateral countermovement jumps (CMJs), calf and squat plyometric jumps, and short sprints). Before and after training, performance was assessed by 10 and 30 m (10 and 30 m) sprint times, best ([RSA.sub.best]) and mean ([RSA.sub.mean] ) times on a repeated shuttle sprint ability test, a CMJ, and a hopping (Hop) test. After training, except for 10 m (p = 0.22), all performances were significantly improved in both groups (all p's < 0.05). Relative changes in 30 m (-2.1 [+ or -] 2.0%) were similar for both groups (p = 0.45). RS training induced greater improvement in [RSA.sub.best] (-2.90 [+ or -] 2.1 vs. -0.08 [+ or -] 3.3%, p = 0.04) and tended to enhance [RSA.sub.mean] more (-2.61 [+ or -] 2.8 vs. -0.75 [+ or -] 2.5%, p= 0.10, effect size [ES] =0.70) than ExpS. In contrast, ExpS tended to induce greater improvements in CMJ (14.8 [+ or -] 7.7 vs. 6.8 [+ or -] 3.7%, p = 0.02) and Hop height (27.5 [+ or -] 19.2 vs. 13.5 [+ or -] 13.2%, p = 0.08, ES = 0.9) compared with RS. Improvements in the repeated shuttle sprint test were only observed after RS training, whereas CMJ height was only increased after ExpS. Because RS and ExpS were equally efficient at enhancing maximal sprinting speed, RS training-induced improvements in RSA were likely more related to progresses in the ability to change direction. KEY WORDS football, team sports, multiple sprint work, adolescent training

The aim of this study was to examine the relationship of 2 different field tests for the assessment of aerobic fitness in soccer players with the multistage 20-m test used for the evaluation of maximum oxygen uptake. Nineteen semi-professional male soccer players (age: 22.8 [+ or -] 2.5 mean [+ or -] SD) performed, under similar conditions, 3 field tests in a counterbalanced order 7 days apart. These tests were the multistage 20-m shuttle run test (MSRT), the Bangsbo test, and the Hoff test. Heart rate was recorded in all tests with telemetry, and the Borg scale was introduced at the end of exercise. Finally, 3-minute post-test lactate concentration was determined. Performance was 11.2 [+ or -] 0.9 levels in the MSRT, 1,658.9 [+ or -] 119.9 m in the Bangsbo test, and 1,798.2 [+ or -] 125.9 m in the Hoff test. There was a significant correlation between the Hoff test and performance in the MSRT (r = 0.49, p < 0.05). The Bangsbo test was not associated with the MSRT score (r = 0.26, p > 0.05). The maximum heart rate achieved in the Bangsbo test was significantly lower compared with that in the MSRT and Hoff test (Bangsbo: 186.6 [+ or -] 9.6, Hoff: 192 [+ or -] 7.6, MSRT: 190.4 [+ or -] 9.3 beats/min, p < 0.05). No difference was found in post-test lactate concentration among the 3 tests. In conclusion, the Hoff test can be used for the assessment of endurance in adult semi-professional soccer players. Coaches and teams could benefit from using the Hoff test that resembles soccer actions for the assessment of players' aerobic fitness. KEY WORDS soccer performance, field testing; multistage shuttle run test, Hoff test, Bangsbo test

The purpose of this study was to examine the effects of static, dynamic, and the combination of static and dynamic stretching within a pre-exercise warm-up on the Illinois agility test (IAT) in soccer players. Nineteen professional soccer players (age = 22.5 [+ or -] 2.5 years, height = 1.79 [+ or -] 0.003 m, body mass = 74.8 [+ or -] 10.9 kg) were tested for agility performance using the IAT after different warm-up protocols consisting of static, dynamic, combined stretching, and no stretching. The players were subgrouped into less and more experienced players (5.12 [+ or -] 0.83 and 8.18 [+ or -] 1.16 years, respectively). There were significant decreases in agility time after no stretching, among no stretching vs. static stretching; after dynamic stretching, among static vs. dynamic stretching; and after dynamic stretching, among dynamic vs. combined stretching during warm-ups for the agility: mean [+ or -] SD data were 14.18 [+ or -] 0.66 seconds (no stretch), 14.90 [+ or -] 0.38 seconds (static), 13.95 [+ or -] 0.32 seconds (dynamic), and 14.50 [+ or -] 0.35 seconds (combined). There was significant difference between less and more experienced players after no stretching and dynamic stretching. There was significant decrease in agility time following dynamic stretching vs. static stretching in both less and more experienced players. Static stretching does not appear to be detrimental to agility performance when combined with dynamic warm-up for professional soccer players. However, dynamic stretching during the warm-up was most effective as preparation for agility performance. The data from this study suggest that more experienced players demonstrate better agility skills due to years of training and playing soccer. KEY WORDS football, movement, performance, dynamic warm-up