摘要:

Using a common framework, this paper presents a survey of the major world sports rating systems (WSRSs) in skiing (sponsored by the International Skiing Federation (FIS)), men's tennis (Association of Tennis Professionals (ATP)), women's tennis (Women's Tennis Association (WTA)), soccer (Federation of International Football Associations (FIFA)) and golf (Royal and Ancient Golf Club of St Andrews). These systems are not otherwise available in the literature. Each of the WSRSs has three phases: first, the observed results are weighted to provide points for each competition; second, these points are combined to provide a seasonal value; third, the seasonal values are combined to provide a rating. The final result or placement (and not the score or time) is the most important factor in determining points for a given competition. In skiing, men's tennis and women's tennis, the rating is calculated from results over one season, while three seasons are used in golf and six seasons are used in soccer. In cross-country skiing and men's tennis, the seasonal value is calculated from the sum of the best values from that season's competitions. In alpine skiing and women's tennis, the sum of all values from that season's competitions is used. In golf and soccer, an averaging process is used. Besides potentially encouraging more entries, a 'best' system and one using all values also generates simple integer ratings rather than decimal ratings as are obtained with an averaging system. The simplest system is that of FIS in skiing, where one table of points is used for all alpine and cross-country disciplines. In contrast, considering that soccer (as a sport) prides itself on the simplicity of the game, it is surprising that FIFA's system is so complex, It is also surprising in soccer that a 'friendly' (often a pick-up exhibition used for player development) counts two-thirds as much as does a World Cup final played before a worldwide TV audience. It is hoped that this survey will serve as a valuable resource for those studying sports rating systems.

ISSN:0266-4763    

DOI:10.1080/02664769723387

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

An optimization problem which provides a new characterization for ridge regression is discussed. A variant of this optimization problem leads to a new family of biased estimators that includes the Stein estimation method and principal components regression as particular cases. The whole approach is illustrated on the basis of real data sets.

ISSN:0266-4763    

DOI:10.1080/02664769723396

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

In long-term field trials comparing different sequences of crops and husbandry practices, the identification and understanding of trends in productivity over time is an important issue of sustainable crop production. This paper presents a statistical technique for the estimation of time trends in yield variables of a seasonal annual crop under continuous cropping. The estimation procedure incorporates the correlation structure, which is assumed to follow first-order autocorrelation in the errors that arise over time on the same plot. Because large differences in annual rainfall have a major effect on crop performance, rainfall has been allowed for in the estimation of the time trends. Expressions for the number of years (time) required to detect statistically significant time trends have been obtained. Illustrations are based on a 7-year data set of grain and straw yields from a trial in northern Syria. Although agronomic interpretation is not intended in this paper, the barley yield data indicated that a significant time trend can apparently be detected even in a suboptimal data set of 7 years' duration.

ISSN:0266-4763    

DOI:10.1080/02664769723404

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

An investigation of the prices of eight individual stocks showed that pricechange returns are significantly less complex than are time-dependent returns. Timedependent returns computed every 15, 30 and 45 minutes were found to be more complex, using a complexity measure. Complexity is quantified by measuring the number of times that the estimated correlation dimension of an observed series is multiplied by when its original sequence is randomly shuffled.

ISSN:0266-4763    

DOI:10.1080/02664769723413

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

This paper presents procedures for the selection of a new sampling scheme called 'single sampling scheme' (SSS). It presents a compact table for the selection of an SSS indexed by various combinations of entry parameters. The advantages of SSSs are discussed. The basis for the construction of the table is also given.

ISSN:0266-4763    

DOI:10.1080/02664769723422

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Ranked-set sampling is a widely used sampling procedure when sample observations are expensive or difficult to obtain. It departs from simple random sampling by seeking to spread the observations in the sample widely over the distribution or population. This is achieved by ranking methods which may need to employ concomitant information. The ranked-set sample mean is known to be more efficient than the corresponding simple random sample mean. Instead of the ranked-set sample mean, this paper considers the corresponding optimal estimator: the ranked-set best linear unbiased estimator. This is shown to be more efficient, even for normal data, but particularly for skew data, such as from an exponential distribution. The corresponding forms of the estimators are quite distinct from the ranked-set sample mean. Improvement holds where the ordering is perfect or imperfect, with this prospect of improper ordering being explored through the use of concomitants. In addition, the corresponding optimal linear estimator of a scale parameter is also discussed. The results are applied to a biological problem that involves the estimation of root weights for experimental plants, where the expense of measurement implies the need to minimize the number of observations taken.

ISSN:0266-4763    

DOI:10.1080/02664769723431

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The exact distribution of an analysis of variance estimator of a variance component is obtained by determining its quantiles on the basis of R. B. Davies' algorithm. A plot of these quantiles provides useful information concerning the efficiency of the estimator, including the extent to which it can be negative. Furthermore, the variability in the values of each quantile is assessed by varying the values of the variance components for the model under consideration. The maximum and minimum of such quantile values can then be determined. A plot of the maxima and minima for various selected quantiles produces the so-called 'quantile dispersion graphs'. These graphs can be used to provide a comprehensive picture of the quality of estimation obtained with a particular design. They also provide an effective graphical tool for comparing designs on the basis of their estimation capabilities.

ISSN:0266-4763    

DOI:10.1080/02664769723440

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

This paper describes a method for estimating regime switches in non-monotonic relationships, using polynomial regressions. Data from the UK financial services industry are used to illustrate the technique. The methodology provides a means of statistically ascertaining the existence of turning points, as well as a means of locating them, should they exist. While the methodology is most suited to applications that involve cross-sectional data, it may also be useful in short-horizon time series turning point prediction.

ISSN:0266-4763    

DOI:10.1080/02664769723459

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The combined array provides a powerful, more statistically rigorous alternative to Taguchi's crossed-array approach to robust parameter design. The combined array assumes a single linear model in the control and the noise factors. One may then find conditions for the control factors which will minimize an appropriate loss function that involves the noise factors. The most appropriate loss function is often simply the resulting process variance, recognizing that the noise factors are actually random effects in the process. Because the major focus of such an experiment is to optimize the estimated process variance, it is vital to understand the resulting prediction properties. This paper develops the mean squared error for the estimated process variance for the combined array approach, under the assumption that the model is correctly specified. Specific combined arrays are compared for robustness. A practical example outlines how this approach may be used to select appropriate combined arrays within a particular experimental situation.

ISSN:0266-4763    

DOI:10.1080/02664769723468

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

ISSN:0266-4763    

DOI:10.1080/02664769723477

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor