Lassoing The Momentum In Professional Basketball Games

On the basis of Chen and Fan(2018)[1],this paper define momentum with two different methods,which use the slope of score difference in a period of time and the time of maintaining the continuous change in score difference,which is abbreviated as slope of momentum and time of momentum.In addition,it finds that momentum can significantly affect the game and the more momentum the team has,the more likely it is to win.Then,we focuse on the analysis of the impact of various sports technical indicators on momentum,which technical indicators can significantly affect momentum.Finally,we extract valuable sports factors to quantify the momentum's values in a basketball game and use Elastic Net to extract factors that affecting the momentum's values,as a result,the coefficient and significance level of each factor are obtained by linear regression.Two conclusions are drawn from the study,First,it is found that timeout,rebound and so on have positive effect on the momentum of home team,in addition,foul and turnover ect.have negative effect on the momentum of home team.Second,momentum can significantly affect the winning percentage of the game,by comparing the results under two different definitions,we think that slope momentum is much more fit the actual situation of the game.Finally,we use Wald-Wolfowitz run test and Bayesian factor to test "hot-hand" effect on momentum,the result shows that the momentum during the season does not have 'hot-hand' effect,while the team during the momentum internal occurrence conforms to the win-win characteristics.