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1.
Abstract

Previous research has shown that experts exhibit superior response selection and skill execution during performance in youth sport. The purpose of this study was to examine differences in cognitive and skill execution components of game performance in young baseball players (N = 159) with, varying levels of expertise. Three levels of expertise (low-, average-, and high-skilled players) were identified at each age level (7, 8, 9, and 10 years of age). Game performance was videotaped, and measures of skill execution (throwing accuracy, throwing force, fielding, catching, batting average, and batting contact) and cognitive components (positioning, decisions) were developed from observational analysis. The results indicated that baseball skill execution during game play maximally discriminated expertise levels.  相似文献   

2.
Youth tennis experts' tactical problem representations have been linked to their superior response selections during competition (McPherson & Thomas, 1989). To expand this research to adults, collegiate varsity (experts, n = 6) and beginner (novices, n = 6) female tennis players participated in an interview session to elicit problem representations and solutions to six tennis game situations. Interviews, transcribed verbatim, were coded for accuracy in solutions to each situation. Novices did not generate any solutions (actions), while experts generated similar and tactical solutions. Quantitative analysis of verbal data revealed expertise differences in problem representations and solution processes. Mann-Whitney U tests revealed that experts accessed more tactical and associated response selection and response execution concepts than novices. Findings indicate that experts will generate specialized cognitive processes to develop, monitor, and regulate their condition profiles and action plans during competition.  相似文献   

3.
Abstract

Research examining problem representations of individuals during task performance is advancing our understanding of information processing and expertise in a variety of sports. However, few studies using similar methodology have been conducted on individuals of various competitive standards in one domain in similar contexts. This study examined problem representations of adult advanced beginners and entry-level professionals accessed during singles tennis competition (n = 12). These groups were selected to represent players with performance skills that were different from those studied previously (i.e. adult beginners and varsity players). Immediate recall and planning interviews were conducted between points during singles tennis competition. Players competed within their respective expertise groups. Verbal reports were transcribed verbatim and concepts were scored according to a model of protocol structure. Several multivariate analyses of variance were conducted on rank scores for measures of concept content and structure using the L-statistic. Entry-level professionals exhibited more advanced problem representations than advanced beginners regardless of interview type. These findings together with those of previous research suggest adaptations in long-term memory profiles with increases in performance skills. For example, beginners lacked action plan and current event profiles because they generated goals and reiterated game events during both interviews. Advanced beginners, who had better performance skills than beginners, exhibited rudimentary action plan profiles and deficient current event profiles because they generated and monitored several detailed actions related to the current context during recall interviews and generated only a few goals during planning interviews. In contrast, varsity players and professionals processed tactical information in the current context and beyond denoting the existence of both action plan and current event profiles. Varsity players, with inferior performance skills than professionals, exhibited fewer and less associated tactical concepts than professionals during both interviews.  相似文献   

4.
Abstract

In this study we compared the kinematic features of the throwing motion between young baseball players of different age groups. Forty‐four Japanese baseball players aged 6.1 to 12.3 years who regularly played baseball, including pitchers and position players, had their throwing actions analyzed three‐dimensionally using high speed videography. Of this sample, 26 players aged above 9 years of age were categorized as the senior group, while the remaining 18 were categorized as the junior group. Senior group throwers had greater height and body mass, and produced a greater ball speed than junior group throwers. The throwing arm movement of senior group throwers was similar to that of adult skilled players. However, in the junior group throwers, the shoulder horizontal adduction angle was larger during the arm acceleration phase, and the maximum angular velocities of elbow extension and shoulder internal rotation occurred later than in senior group throwers. These results indicate that players aged above 9 years can acquire a mature throwing arm movement, while players younger than that will use an immature motion. A possible reason why these differences were shown is that the official baseball is relatively heavy for junior group throwers; they would be better advised to use a lighter ball in throwing practice.  相似文献   

5.
Professional baseball players have attempted to illegally modify baseball bats in the hopes of increasing bat speed and thus the distance travelled by batted balls. To date, no low-cost, non-invasive, real-time solution exists to this problem. Previously proposed solutions to this problem that involved using radar to measure the scatter signature of a scanned baseball bat were found to be extremely expensive. Ultrasound technology offers the ability to provide equivalent scatter signature measurements as compared to radar technology at a much lower cost and level of complexity while still operating in real time. We therefore present an ultrasound-based implementation of a prototype for a hand-held scanner unit designed to detect illegally modified baseball bats. A detailed discussion of the performance enhancements resulting from illegally modifying a baseball bat will be provided and an analysis of the attenuative properties of wood will be presented to determine appropriate sample rates for the ultrasound unit. Data acquisition issues encountered in prototyping the scanner will be examined and measurement data for both solid wood bats and modified bats will be evaluated to determine the effectiveness of the ultrasound-based data acquisition unit and the prototype’s ability to distinguish between both types of scatter signatures.  相似文献   

6.
ABSTRACT

The recruitment of athletes with limited resources is a global problem in professional sports. In US Major League Baseball, the experience of the Oakland Athletics’ general manager in the last decade turned his “Moneyball” model into a synonym of quantitative analysis in the transfer market of baseball players. His strategy focused on hiring players with outstanding technical skills but relatively low market value. This study adapted this model to the framework of a multiple criteria decision aid (MCDA), by selecting undervalued players who have complementary abilities. The novelty here refers to the joint use of four algorithms explored by the composition of probabilistic preferences (CPP) (i.e., ranking, classification, dynamic evaluation and regularity analysis) and their application to soccer player performance evaluation. The new model analysed the recent transfer of a left-back soccer player to Europe. The results indicated 12 opportunities for better investment, among 32 left and right-back players considered. Two years later, the value of the same player was considerably lower. He played only five matches in the 2018–2019 season, without scoring or providing any assists. On the other hand, the players better classified by the CPP-MB model presented higher performances and market values.  相似文献   

7.
Research examining problem representations of individuals during task performance is advancing our understanding of information processing and expertise in a variety of sports. However, few studies using similar methodology have been conducted on individuals of various competitive standards in one domain in similar contexts. This study examined problem representations of adult advanced beginners and entry-level professionals accessed during singles tennis competition (n = 12). These groups were selected to represent players with performance skills that were different from those studied previously (i.e. adult beginners and varsity players). Immediate recall and planning interviews were conducted between points during singles tennis competition. Players competed within their respective expertise groups. Verbal reports were transcribed verbatim and concepts were scored according to a model of protocol structure. Several multivariate analyses of variance were conducted on rank scores for measures of concept content and structure using the L-statistic. Entry-level professionals exhibited more advanced problem representations than advanced beginners regardless of interview type. These findings together with those of previous research suggest adaptations in long-term memory profiles with increases in performance skills. For example, beginners lacked action plan and current event profiles because they generated goals and reiterated game events during both interviews. Advanced beginners, who had better performance skills than beginners, exhibited rudimentary action plan profiles and deficient current event profiles because they generated and monitored several detailed actions related to the current context during recall interviews and generated only a few goals during planning interviews. In contrast, varsity players and professionals processed tactical information in the current context and beyond denoting the existence of both action plan and current event profiles. Varsity players, with inferior performance skills than professionals, exhibited fewer and less associated tactical concepts than professionals during both interviews.  相似文献   

8.
Abstract

Twenty-one male freshmen baseball players at the University of Maryland were randomly placed in three groups of equal size. Two groups supplemented a baseball throwing program by specific overload training. One group threw weighted baseballs while the other used a pulley device to resist the mechanics of throwing. Training was carried out for a 6-week period. Both training groups experienced significant within-group increases in throwing velocity as a result of training, with no significant change in accuracy. However, no significant difference was indicated among training groups and a control group.  相似文献   

9.
In this study we compared the kinematic features of the throwing motion between young baseball players of different age groups. Forty-four Japanese baseball players aged 6.1 to 12.3 years who regularly played baseball, including pitchers and position players, had their throwing actions analyzed three-dimensionally using high speed videography. Of this sample, 26 players aged above 9 years of age were categorized as the senior group, while the remaining 18 were categorized as the junior group. Senior group throwers had greater height and body mass, and produced a greater ball speed than junior group throwers. The throwing arm movement of senior group throwers was similar to that of adult skilled players. However, in the junior group throwers, the shoulder horizontal adduction angle was larger during the arm acceleration phase, and the maximum angular velocities of elbow extension and shoulder internal rotation occurred later than in senior group throwers. These results indicate that players aged above 9 years can acquire a mature throwing arm movement, while players younger than that will use an immature motion. A possible reason why these differences were shown is that the official baseball is relatively heavy for junior group throwers; they would be better advised to use a lighter ball in throwing practice.  相似文献   

10.
Abstract

The purpose of this study was to compare measures of body size in two samples of youth baseball players with normative data from the United States National Center for Health Statistics (NCHS) growth charts. One sample of youth baseball players participated in a local little league. The second sample of youth baseball players were members of eight of the twelve teams participating in the 1995 Dixie Youth World Series. Normative data for the United States (NCHS) were used as comparative data. Two trained anthropometrists measured standing height, sitting height, lower limb height, upper limb length, arm girth, calf girth, tricep skinfold, and abdomen skinfold on all participants. In both samples, pitchers, short stops, and first basemen were a more highly skilled group and exhibited larger body size (greater standing height, sitting height, lower limb height, upper limb length) than children who played at other positions. The standing height of local little league players was similar to the median of reference data at ages 7, 8, and 9 years. The standing height and weight of skilled players in both samples approximated the 75th percentile for standing height and weight at ages 10, 11, 12, and 13 years. The results suggest that baseball players exhibit larger body size than the normal population at young ages. Body size may be an important criterion used by coaches to select and assign young players to certain positions.  相似文献   

11.
The form of 3,684 throws made by 100 players in 7 collegiate baseball games was examined in relation to position, distance, and active and inactive situations. All throws made from the first pitch to the last out for 94 half innings were videotaped from the stands. The results showed that the interrater reliability of task, environment, and performance measures were all acceptable to excellent (percentage of agreement was at least 80%), indicating that qualitative aspects of throwing can be reliably measured in an actual sport context. Alternatives to the most advanced pattern were observed at least half the time for catchers and infielders at most distances in both active and inactive situations andfor pitchers and outfielders only in inactive situations.  相似文献   

12.
Abstract

This study was designed to examine the perceptual and attentional processes associated with the effects of administering a cost-benefit precuing paradigm to intermediate and advance-level baseball batters. Psychophysiological and performance data obtained from 10 advanced and 10 intermediate-level players were compared. A total of 400 pitches (200 fastballs, 200 curveballs) was randomly presented via a large projection screen, and participants pressed one of two buttons to indicate the type of pitch thrown. Verbal precues were given for 300 of the pitches. Of those, 75% were valid, and 25% were invalid. Electroencephalographic data collected from the Pz location was used to assess the latency and amplitude of P300. Analysis of variance (Skill Level x Precue x Pitch) for P300 and reaction time (RT) indicated that intermediate batters produced shorter P300 latencies, larger P300 amplitudes, longer RTs, and less correct responses than the advanced batters; the effects were more pronounced for the curveballs. These results suggest that intermediate batters are less efficient in their perceptual decision-making processes due to greater limitations in attentional capacity when compared with advanced batters.  相似文献   

13.
Abstract

Nine- to 10-year-old children have difficulty playing baseball using adult rules because pitchers lack the ability to throw the ball over the plate with consistency and batters lack ability to hit erratically thrown balls. Thus a natural field experiment investigated a modification of adult baseball for 9- to 10-year-old children. Instead of one of the players on the opposing team pitching, the coach of the offensive team pitched to the batters. Teams in a league who played baseball by adult rules (traditional league) were compared with teams in a league who played the modified game (nontraditional league), and both these leagues were compared with 11- to 12-year-old teams (older league). Various offensive and defensive activities were recorded by two observers and satisfaction scores were obtained from the players after the games. More offensive and defensive activity occurred in the nontraditional league games than in the traditional and older league games.  相似文献   

14.
Expert and novice tennis players selected from three different age groups (i.e., 10-11 years, 12-13 years, and collegiate adults) were examined for differences in performance skills (i.e., behavioral analyses of video recordings) and problem representations (i.e., verbal report analyses of tape recordings) during matched competition. Factorial analyses of variance on behavioral measures indicated that experts' performances exhibited higher levels of decision and execution than novices, regardless of age. Kruskal-Wallis tests on verbal report measures indicated that experts generated more total, varied, and sophisticated condition and action concepts than novices. Within experts, adults accessed more sophisticated problem representations than youth. Both current event and action plan profiles guided and mediated adult experts' response selections and executions, respectively. Youth experts primarily used action plan profiles to guide their response selections. Novices, regardless of age, accessed weak problem representations.  相似文献   

15.
Abstract

This study examined the birth distribution for adolescent (i.e. <20 years) and mature age players (i.e. ≥20 years) selected in the Australian Football League (AFL) National Draft between 2001 and 2012. Birth-date information was accessed for all first time AFL national draftees and players were then classified as either adolescent (N = 736) or mature age (N = 70) draftees. Chi-squared analysis showed a clear bias in the birth distribution of adolescent draftees towards players born in the first part of the classification period for both quartile (P < 0.001) and half-year (P < 0.001) compared to the Australian national population. There was a reverse relative age effect (RAE) for mature age draftees, with a significant bias towards players born in the latter part of the selection period for both quartile (P = 0.047) and half-year (P = 0.028) compared to the Australian national population. The selection bias towards relatively older players in adolescent AFL draftees may be related to advanced physical and psychological maturity, and exposure to higher-level coaching compared to their younger counterparts. The reverse RAE in mature age draftees is a novel finding and supports the need for strategies to encourage continued participation pathways for talented Australian football players born later in the selection year.  相似文献   

16.
Abstract

The primary purpose of this investigation was to determine the relative importance of the attributes that student–athletes use when determining their choice of a university. A second purpose was to compare previous athletic institutional choice studies with the results of this study to determine if the most important attributes were similar and to compare and contrast methodologies. Six hundred five Division I student–athletes (344 baseball players and 261 softball players) from all eight national geographic regions of the NCAA participated in this study. The experimental procedure was based on Information Integration Theory and a 210 fractional factorial design that resulted in 32 “choice sets.” These choice sets were composed of universities described by 10 attributes. This framework required that the student–athletes choose from among three university profiles, thereby realistically simulating the decision process. The results for the aggregate sample show that the “Amount of Scholarship” attribute was the most important factor in the institutional choice process. Many demographic variables were analyzed (sex, race, amount of scholarship received as a freshman, amount of perceived financial need, self-reported grade-point average, questionnaire completion procedures, in-state/out-of-state status, NCAA region, and rank in high school) in conjunction with the choice set data in a post-hoc framework. The results for a subset of these variables are reported in this paper; differences (in the order of importance of the attributes) were found among groups. A primary finding of this study is that a student–athlete's perceived financial need has a critical impact on the institutional choice process. A second important finding is that, although “Amount of Scholarship” was determined to be the most important attribute, this result stands in stark contrast to previous studies that have investigated the institutional choice process of student–athletes.  相似文献   

17.
In this study, we examined how perceptual-motor expertise and watching experience contribute to anticipating the outcome of opponents' attacking actions in beach volleyball. To this end, we invited 8 expert beach volleyball players, 8 expert coaches, 8 expert referees, and 8 control participants with no beach volleyball experience to watch videos of attack sequences that were occluded at three different times and to predict the outcome of these situations. Results showed that expert players and coaches (who were both perceptual-motor experts) outperformed the expert referees (who were watching experts but did not have the same motor expertise) and the control group in the latest occlusion condition (i.e., at spiker-ball contact). This finding suggests that perceptual-motor expertise may contribute to successful action anticipation in beach volleyball.  相似文献   

18.
One of the major challenges that faces nation-builders in postcolonial societies is the incorporation of subaltern groups, particularly aboriginal peoples, into a collective national project. One vehicle for addressing this challenge is sport with schools being amongst the most important venues. This article offers an empirical study of the role of aboriginal players in Taiwanese baseball. By examining the schooling and historic achievements of aboriginal players in the Nenggao and Hongye teams and the role of aboriginal players during the more recent post-martial law period, the study challenges some commonly held views concerning the relationship between baseball and Taiwanese national identity. In particular, the article analyzes the role of the state in its use of baseball to support the co-option of aboriginal players for the nation-building project. The study concludes that the state, regardless of which ruling elite is in power, has consistently manipulated Taiwan's indigenous peoples, not least through the education system, in order to achieve certain political objectives, specifically in relation to nation-building. Furthermore, although baseball remains an important avenue for the social and economic advancement of individual aborigines, recurrent scandals linked to exploitation have been consistent characteristics of state policy.  相似文献   

19.
Abstract

In 1938, Mormon missionaries from North America, under the leadership of Frederick Salem Williams, formed an athletic club, Club Atlético Los Mormones (‘The Mormons Athletic Club’, CALM), in Buenos Aires, Argentina. CALM would sponsor professional teams in baseball, softball, and basketball, all bearing the name Los Mormones (‘The Mormons’). Los Mormones won three league championships in the four years they played baseball and four championships in the five years they played softball. Two of their basketball players would become national all-stars, one of whom would represent Argentina at the South American Championship in 1940. Williams served as president of the softball league and vice president of the baseball league. Los Mormones’ story is outlined and situated in relation to the various discourses that, woven together, constitute the cultural context of modern Argentine sport: physical culture and modernity, United States-Argentine relations, amateurism versus professionalism, and the spread of North American sports to Latin America.  相似文献   

20.
Abstract

In this study, we examined the relations between biological maturity status, body mass index, age, and perceptions of adult autonomy support in the context of youth soccer. A total of 70 female and 43 male soccer players, aged 9 – 15 years, completed three adult-specific versions (i.e. mother, father, coach) of the perceived autonomy support subscale from the Interpersonal Style Scale. The participants' percent predicted adult stature was used as an estimate of biological maturity status. Multiple linear regression analyses revealed that advanced maturity status in male players predicted lower perceptions of autonomy support from the coach. Maturity status was unrelated to perceptions of autonomy support from the coach in female soccer players, and paternal and maternal autonomy support in male and female players. Age and body mass index were unrelated to perceptions of adult (i.e. coach, mother, father) autonomy support in male and female players.  相似文献   

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