摘要:

Often sports announcers, particularly in baseball, provide the listener with exaggerated information concerning a player's performance. For example, we may be told that Dave Winfield, a popular baseball player, has hit safely in 8 of his last 17 chances (a batting average of .471). This is biased, or selected information, as the “17” was chosen to maximize the reported percentage. We model this as observing a maximum success rate of a Bernoulli process and show how to construct the likelihood function for a player's true batting ability. The likelihood function is a high-degree polynomial, but it can be computed exactly. Alternatively, the problem yields to solutions based on either the EM algorithm or Gibbs sampling. Using these techniques, we compute maximum likelihood estimators, Bayes estimators, and associated measures of error. We also show how to approximate the likelihood using a Brownian motion calculation. We find that although constructing good estimators from selected information is difficult, we seem to be able to estimate better than expected, particularly when using prior information. The estimators are illustrated with data from the 1992 Major League Baseball season.

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476846

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A recent article inSports Illustratedargues that the National Football League (NFL) preseason schedule should be eliminated because the games are meaningless, feature subpar players, and are of no interest to fans. In this article we challenge this view, using statistical techniques to analyze both the outcome of preseason games and their value as a predictor of regular season performance. Our analysis is based on the application of a rank-order tournament model to the NFL labor market. The model explains preseason results in terms of the competition for positions on teams. Two implications are that the outcome of preseason games should reflect the labor market characteristics of the participating teams and that a team's preseason record should be positively related to its regular season record. Both of these hypotheses are consistent with our analysis of NFL data from 1970 through 1991.

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476847

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An incremental clustering algorithm is described and applied to 1992 Olympic heptathlon data to produce characterizations of groups of the leading athletes. Results are compared with those obtained by classical clustering techniques. The incremental technique is of ordernlogn, wherenis the number of observational units and can be combined with Classification and Regression Trees (CART) to obtain descriptions of the clusters. Brief reference is made to other possible ways of analyzing the data, including the use of correspondence analysis. The analysis can be used to show which events are most critical in determining the better class of heptathlete.

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476848

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This article describes statistical research on the academic performance of student-athletes in college sports programs. We describe several statistical models used in the prediction of academic success defined by college persistence and graduation. Using longitudinal data on the academic performances of about 3,000 student-athletes in NCAA Division I collegiate sports programs, we formulate logit and multilevel logit statistical models for the prediction of graduation rates. These prediction models are based on academic, demographic, and athletic variables, and are used to account for differences in both the students and the colleges. These results show (1) moderate but significant relationships between precollege academic characteristics and college graduation, (2) small but significant differential validity of prediction between major student-athlete groups, (3) notable college-level variance in the average graduation rate, (4) small but significant within-college relationships between precollege academic characteristics and college graduation, and (5) differences between colleges accounted for by institutional graduation rates. We highlight statistical issues about the application of logit and multilevel models and discuss substantive issues about the current implications of these results.

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476849

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

We investigate the effect of the expulsion of a player on the outcome of a soccer match by means of a probability model for the score. We propose estimators of the expulsion effect that are independent of the relative strength of the teams. We use the estimates to illustrate the expulsion effect on the outcome of a match.

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476850

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The difference between the home and visiting teams' scores in a sports contest is modeled as a Brownian motion process defined ont∈ (0, 1), with drift μ points in favor of the home team and variance [sgrave]2. The model obtains a simple relationship between the home team's lead (or deficit)lat timetand the probability of victory for the home team. The model provides a good fit to the results of 493 professional basketball games from the 1991-1992 National Basketball Association (NBA) season. The model is applied to the progress of baseball scores, a process that would appear to be too discrete to be adequately modeled by the Brownian motion process. Surprisingly, the Brownian motion model matches previous calculations for baseball reasonably well.

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476851

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Visualizing Data.William S. Cleveland. Summit, NJ: Hobart Press, 1993. 360 pp. $40. Reviewed by A. H. WelshThe Australian National University

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476852

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Spatial Statistics and Digital Image AnalysisJulian Besag and James Simpson, Panel Co-Chairs. National Research Council, National Academy Press, 1991, 234 pp. $25 plus $4 shipping.

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476853

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This article has no abstract

ISSN:0162-1459    

DOI:10.1080/01621459.1994.10476805

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor