Predicting the NBA Playoff Using SVM
Total Page：16
File Type：pdf, Size：1020Kb
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by MAT Journals Journal of Web Development and Web Designing Volume 1 Issue 1 Predicting the NBA Playoff Using SVM Amruta Jadhav, Sandhya Das, Savita Khatode, Rohini Degaonkar Department of Computer Science and Engineering, J.N.E.C, Aurangabad, India E-mail: [email protected] Abstract In this paper, we examine the use of Support Vector machine as a tool for predicting the success of basketball teams in the National Basketball Association (NBA). Statistics for 2012–2015 NBA games were collected and used to examine and predict the outcome of NBA playoffs. The best results were able to correctly predict the winning team is 88 percent. Further, we investigate which subset of features input to the SVM model are the most salient features for prediction. Keywords: SVM algorithm, playoffs, prediction, NBA INTRODUCTION divisions Northwest, Pacific, Southwest. The National Basketball Association Atlantic has five teams Boston Celtics, (NBA) is that the comfort Brooklyn Nets, New York Knicks, station sport league in North America and Philadelphia 76ers Toronto raptors. is wide thought-about to be the Central has five teams Chicago Bulls, most effective comfort station sport league Cleveland Cavaliers, Detroit Pistons, within the world. It is thirty groups within Indiana pacers, Milwaukee Bucks. which twenty nine groups are from U.S. a Southeast has five teams Atlanta Hawks, nd one team from Canada. The league Charlotte Hornets, Miami Heat, Orlando adopted the name National Basketball Magic, Washington Wizards. Northwest Association on August 3, 1949. The has five teams Denver Nuggests, current league organization divides thirty Minnesota Timberwolves, Oklahoma City teams into Eastern Conference and Thunder, Portland Trail Blazers, Utah Western Conference. Eastern Conference Jazz. Pacific has five teams Golden state has three divisions Atlantic, Central, Warriors, Los Angeles Clippers, Los Southeast. Western Conference has three Angeles Lakers, Phoenix Suns, 1 Page 1-6 © MAT Journals 2016. All Rights Reserved Journal of Web Development and Web Designing Volume 1 Issue 1 Sacramento Kings. Southwest has five Cernegie Mellon University (Jackie B. teams Dallas Mavericks, Houston Yang, 2012) used support vector machines Rockets, Memphis Grizzlies, New Orleans that made use of the kernel functions. Pelicans, San Antonio Spurs [1, 2]. Their model did not perform well on the attributes they used. The students started In February, the regular season pauses to with 14 attributes per team but they did celebrate the annual NBA All-Star Game. not investigate the possibility that using all Fans vote throughout the United States, of these attributes might lead to over Canada and on the Internet and the top fitting. This might be the case in this vote-getters at each position in each research looking at the performance of conference are given a starting spot on 55%. In 55% of 30 actual played games, their conference's All-Star team. Around the winner was correctly predicted [3, 4]. the middle of April, the regular season ends. The Rookie of the Year Award is Wei (Wei, 2012) has examined the awarded to the most outstanding first-year utilization of naive Bayes. Wei used home player. The Most Improved Player and away winning rates. Whereas Jones Award is awarded to the player who is (Jones, 2007) showed the deemed to have shown the most existence of the house advantage; mistreat improvement from the previous season. ment this home and away winning The Defensive Player of the Year rates did not influence Wei’s predictions. Award is awarded to the league's best The predictions performed even defender. The Coach of the Year Award is worse whereas accounting for the seasons awarded to the coach that has made the home/away records. This would most positive difference to a team. possibly indicate the playoffs home The Most Valuable Player Award is given advantage being very totally different to the player deemed the most valuable for from the season’s home advantage. While (his team) that season. the best performing team gets the home advantage it is interesting to find out RELATED WORKS whether the best teams wins because of Several researches have been done to the home advantage or because they are predict the results of the National simply the better team. Basketball Association. Students from 2 Page 1-6 © MAT Journals 2016. All Rights Reserved Journal of Web Development and Web Designing Volume 1 Issue 1 DATASETS AND FEATURES available, different models will be run. This project collects data from some non- Given previous research, the Naive Bayes profit websites, which publish NBA game may perform well but other algorithms statistics data available to public. The have to be tried. The models will be following section will introduce sources of trained on 8 of the 9 years and tested on data used in this project. the remaining one. The model that performs best will be used to predict the Data Sources 2012 playoffs that have just finished. In this project, data used for model Simulating all of the playoff games in one training and testing, Basketball- time will lead to difficulties measuring reference.com is our major data source. performance. For example: when Miami Basketball-reference.com is one of the plays Boston and the model predicts most famous one for those sports data Miami to survive, while in fact Boston is miners, and has been used in many going to win, the next round will be experiments. It was created in 2003 and different in the model compared to reality. data requests are comprehensive, In this case it is impossible to measure relatively well organized, straightforward whether the model was right on this next and easy to navigate and utilize. round because this round is never played in this particular setting. This is why the For this project about 3 years of NBA playoffs will be predicted round by round. game statistics data has been collected, which came from 2012–2013 season to Table 1: NBA Statistics Explanation. 2014–15 season. These 3 years of data Attributes Explanation would have better consistency and MP Minutes Played FG Field Goals applicability to new season predictions. FGA Field Goal Attempts Attributes use in our dataset are explained 3P 3-Point Field Goals in Table 1. 3PA 3-Point Field Goal Attempts 3P% 3-Point Field Goals Percentage Building the Model FT Free Throws The next step in the process of predicting FTA Free Throw Attempts FT% Free Throw Percentage is building a model on the information that ORB Offensive Rebounds is found. With the information that is 3 Page 1-6 © MAT Journals 2016. All Rights Reserved Journal of Web Development and Web Designing Volume 1 Issue 1 DRB Defensive Rebounds teams seeding number, playoff round and TRB Total Rebounds the number of won games during the best- AST Assists of-seven, until then, are added as W/L% Win Loss Percentage attributes. PER Player Efficiency Rating FG Field Goals FGA Field Goal Attempts SVM FG% Field Goals Percentage We also modelled our problem with a 2P 2-Point Field Goals support vector machine to predict whether 2PA 2-Point Field Goal Attempts or not a streak will occur. To date, few 2P% 2-Point Field Goals Percentage supervised learning algorithms have STL Steals BLK Blocks outperformed SVMs; perhaps the most TOV Turnovers alluring property of SVMs is that we can PF Personal Fouls utilize their symbiosis with kernels. This PTS Points lets us create high or infinite dimensional PTS/G feature vectors, allowing us to capture the G Season Game subtle interactions between features, which is particularly important for our Playoffs dataset because it contains so many As mentioned earlier, the playoffs are a intertwined and interdependent features. best-of-seven knockout tournament. Eight Thus, the SVM presents an ideal teams from the west will play each other, classification model that does not limit our as well as eight teams in the east. The ability to utilize a dense, high dimensional western and eastern champions finally feature vector to determine the state of the play each other in the NBA final. The game. NBA playoffs consist of four rounds. First round, conference semi-finals, conference One disadvantage of SVMs, however, is finals and NBA finals. The teams will be that they are easily susceptible to over seeded given their strength during the fitting because they work in such a high regular season. The seeds light are very dimensional feature space. Since it is important because the lower seed means likely that the extracted data will become this team, that performed better, will have linearly separable, we run the danger of the home advantage. Given these facts, the the model learning hidden attributes of our 4 Page 1-6 © MAT Journals 2016. All Rights Reserved Journal of Web Development and Web Designing Volume 1 Issue 1 data rather than the more general trends we are looking for. SVMs constructed in this manner work to maximize the geometric margin for every point by constructing a separating hyper plane in high-dimensional space (as most data sets are not linearly separable) that classifies as many points correctly with the largest margin possible. Fig. 2: Win/Loss and PTS. RESULTS AND DISCUSSION Our model produces 88% accuracy on testing dataset. Figure 1 shows SVM plotting points on attribute Win/Loss and PER. Separate hyper plane can be drawn easily on this attribute on labelled class result. Figure 2 shows SVM plotting Fig. 3: ORB and DRB. points on attribute Win/Loss and PTS. Separate hyper plane can be drawn easily CONCLUSION on this attribute on labelled class result.