The competitiveness of games in professional sports leagues

Abstract

A sports game is about competition. The competitiveness of a game is important in terms of fan interest as a non-competitive game will cause fans attending a game to lose interest and be more likely to leave the game early. Fans viewing the game live will find another activity to do. Teams ahead or behind in a non-competitive game may also be more likely to substitute reserve players to reduce risk of injury to key players or gain experience for lesser-used players. Changes in how a team plays in a non-competitive game also impact secondary competitions such as betting or fantasy sports due to player behavior changes in a non-competitive game. In this work we examine the competitiveness of games in six professional sports leagues. We obtain the list of scoring events for each game and map each event into a discrete segment, based on minutes played or outs recorded, for each game. A significant advantage of our approach is that all sports are analyzed in the same manner with the only difference between leagues being the number of segments into which each game is divided. By dividing each segment number by the total number of segments for the league we can compute a common percentage-based timeline to compare the competitiveness of different leagues through the course of a game. A distinguishing feature of our work is that we explore a number of potential measures of competitiveness using our data. These measures include whether a team is leading, whether a team is leading by more than a given number of scores, whether a team is in the lead and wins the game, whether a team is in the lead for good, whether a team already winning goes on to win or stay ahead for good, and the probability that a team with given lead at a given point in the game will win. We analyze the games in each professional sports league using each of these competitiveness metrics and find that MLB games are clearly the least competitive compared with games from each of the other leagues in our study. MLB games have the highest percentage of game segments that are played in less competitive situations. MLS and BPL games tend to be the most competitive in general; largely because about half of game time for these leagues is spent with the game tied. However, if a team does take the lead in one of these leagues then they, along with MLB, have the highest chance that this team will not relinquish the lead. Results for the NFL and NHL show that their games are neither relatively the most or least competitive. We believe variation in the competitiveness of the leagues occurs because of the nature of the sports in terms of how they are played and scored as well as the specific leagues themselves. We go on to find that NFL home teams spend the most amount of game time ahead for good and NHL home teams spend the least. Using this ahead-for-good metric, there is the most amount difference for home and away teams in MLS while there is the least in MLB. Finally we use this same ahead-for-good metric to evaluate the competitiveness performance of all teams across the six leagues in our study. The Denver Broncos of the NFL spent the most game time ahead for good of all professional teams while Chelsea of the BPL spent the least amount of time behind for good. The Golden State Warriors of the NBA and the New England Patriots of the NFL had the most dominant game performance based upon the difference in ahead-for-good versus behind-for-good game time.