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getwd()[1] "/Users/victorcuerdo/Library/CloudStorage/GoogleDrive-victormcuerdo@gmail.com/My Drive/MDC/Special Topics - Sport Analytics/In class activity # 7"baseball = read.csv("baseball.csv")# Subset to only include moneyball years (before 2002)
moneyball = subset(baseball, Year < 2002)# Compute Run Difference
moneyball$RD = moneyball$RS - moneyball$RA# Regression model to predict wins from run difference
WinsReg = lm(W ~ RD, data = moneyball)
summary(WinsReg)
Call:
lm(formula = W ~ RD, data = moneyball)
Residuals:
Min 1Q Median 3Q Max
-14.2662 -2.6509 0.1234 2.9364 11.6570
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 80.881375 0.131157 616.67 <2e-16 ***
RD 0.105766 0.001297 81.55 <2e-16 ***
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 3.939 on 900 degrees of freedom
Multiple R-squared: 0.8808, Adjusted R-squared: 0.8807
F-statistic: 6651 on 1 and 900 DF, p-value: < 2.2e-16# Predict wins for a team that scores 763 and allows 614 runs
newteam = data.frame(RD = 763 - 614) # RD = 149
predict(WinsReg, newteam) 1
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