Centres Of Excellence

To focus on new and emerging areas of research and education, Centres of Excellence have been established within the Institute. These ‘virtual' centres draw on resources from its stakeholders, and interact with them to enhance core competencies

Read More >>

Faculty

Faculty members at IIMB generate knowledge through cutting-edge research in all functional areas of management that would benefit public and private sector companies, and government and society in general.

Read More >>

IIMB Management Review

Journal of Indian Institute of Management Bangalore

IIM Bangalore offers Degree-Granting Programmes, a Diploma Programme, Certificate Programmes and Executive Education Programmes and specialised courses in areas such as entrepreneurship and public policy.

Read More >>

About IIMB

The Indian Institute of Management Bangalore (IIMB) believes in building leaders through holistic, transformative and innovative education

Read More >>

Rank Consistent Bradley-Terry Models for Repeated Tournaments

Akshay Kumar Singh and Shubhabrata Das
2014
Working Paper No
466
Body

The primary objective of this paper is to model the win-loss records of matches in a repeated tournament using the ranks of the teams. The work proposes modifications of Bradley-Terry (BT) model to make the estimation consistent with the ranks of the participating teams. The BT model with restricted maximum likelihood estimation involves too many parameters and the estimates typically lack strict monotonicity. A proposed class of rank-percentile BT models based on different parametric distribution resolves both the issues. Parameter estimation, goodness-of-fit using suitably framed test statistic and its null distribution, change point analysis in a nested model framework, as well as other estimation aspects are discussed in this article. Adaptive variations of the model that allow estimates to alter are also discussed. For demonstration, National Collegiate Athletic Association (NCAA) men and women basketball tournament data are considered. The discussed models provide excellent fit to the historical data using only a few parameters. The fit validates the ranking procedure implemented by the NCAA. The models can be extended in more general tournament structures, as shown through an analysis of results from the Indian Premiere League. The work done has potential for application in the wider domain of paired comparisons.

Key words
Knockout Tournament, Ranking, NCAA, Restricted Maximum Likelihood, Rankpercentile BT model, Round-Based Model, Chi-squared goodness-of-fit
WP_No._466.pdf (473.26 KB)

Rank Consistent Bradley-Terry Models for Repeated Tournaments

Author(s) Name: Akshay Kumar Singh and Shubhabrata Das, 2014
Working Paper No : 466
Abstract:

The primary objective of this paper is to model the win-loss records of matches in a repeated tournament using the ranks of the teams. The work proposes modifications of Bradley-Terry (BT) model to make the estimation consistent with the ranks of the participating teams. The BT model with restricted maximum likelihood estimation involves too many parameters and the estimates typically lack strict monotonicity. A proposed class of rank-percentile BT models based on different parametric distribution resolves both the issues. Parameter estimation, goodness-of-fit using suitably framed test statistic and its null distribution, change point analysis in a nested model framework, as well as other estimation aspects are discussed in this article. Adaptive variations of the model that allow estimates to alter are also discussed. For demonstration, National Collegiate Athletic Association (NCAA) men and women basketball tournament data are considered. The discussed models provide excellent fit to the historical data using only a few parameters. The fit validates the ranking procedure implemented by the NCAA. The models can be extended in more general tournament structures, as shown through an analysis of results from the Indian Premiere League. The work done has potential for application in the wider domain of paired comparisons.

Keywords: Knockout Tournament, Ranking, NCAA, Restricted Maximum Likelihood, Rankpercentile BT model, Round-Based Model, Chi-squared goodness-of-fit
WP_No._466.pdf (473.26 KB)