The Best Predictor of the Winning Percentage The ultimate goal in any sport (besides

Chapter 4, Problem 38

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The Best Predictor of the Winning Percentage The ultimate goal in any sport (besides having fun) is to win. One measure of how well a team does is the winning percentage. In baseball, a lot of effort goes into figuring out the variable that best predicts a teams winning percentage. The following data represent the winning percentages of teams in the National League along with potential explanatory variables based on the 2010 season. Which variable do you think is the best predictor of winning percentage? Why? Team Winning Percentage Runs Home Runs Team Batting Average On-Base Percentage Batting Average Against Team ERA Philadelphia 0.599 772 166 0.260 0.332 0.254 3.67 Atlanta 0.562 738 139 0.258 0.339 0.246 3.56 San Francisco 0.568 697 162 0.257 0.321 0.236 3.36 Chicago Cubs 0.463 685 149 0.257 0.320 0.255 4.18 Florida 0.494 719 152 0.254 0.321 0.261 4.08 LA Dodgers 0.494 667 120 0.252 0.322 0.244 4.01 Washington 0.426 655 149 0.250 0.318 0.266 4.13 Arizona 0.401 713 180 0.250 0.325 0.271 4.81 NY Mets 0.488 656 128 0.249 0.314 0.260 3.70 Houston 0.469 611 108 0.247 0.303 0.261 4.09 San Diego 0.556 665 132 0.246 0.317 0.240 3.39 Pittsburgh 0.352 587 126 0.242 0.304 0.282 5.00 Source: espn.com