| # MAJOR LEAGUE BASEBALL - RUNS PER GAME TREND | |
| # | |
| # discussion at | |
| # 1. http://bayesball.blogspot.ca/2012/07/trends-in-al-run-scoring-using-r.html | |
| # 2. http://bayesball.blogspot.ca/2012/07/trends-in-run-scoring-nl-edition-more-r.html | |
| # 3. http://bayesball.blogspot.ca/2012/08/trends-in-run-scoring-comparing-leagues.html | |
| # | |
| # data source: Baseball Reference | |
| # http://www.baseball-reference.com | |
| # http://www.baseball-reference.com/leagues/AL/bat.shtml | |
| # http://www.baseball-reference.com/leagues/NL/bat.shtml | |
| # | |
| # open with "csv" option (top right corner of the table), | |
| # copy and paste into text editor or Excel, save as CSV file | |
| # | |
| # set working directory | |
| # setwd("K:/data/R_the software/datatrials/baseball/RunsPerGame") | |
| # read the data into a table | |
| ALseason <- read.table(file="ALseasons.csv", sep = ",", header = TRUE) | |
| NLseason <- read.table(file="NLseasons.csv", sep = ",", header = TRUE) | |
| # | |
| # alternate approach to reading NL season, from .txt file | |
| NLseason <- read.table(file="NLseasons.txt", sep = ",", header = TRUE) | |
| # | |
| # | |
| # RUNS SCORED PER GAME | |
| # ==================== | |
| # | |
| # start with American League | |
| # | |
| # very simple plot -- as (x, y) | |
| plot(ALseason$Year, ALseason$R) | |
| # as (y predicted by x) | |
| plot(ALseason$R ~ ALseason$Year) | |
| # | |
| # create new object ALRunScore.LO for loess model | |
| ALRunScore.LO <- loess(ALseason$R ~ ALseason$Year) | |
| ALRunScore.LO.predict <- predict(ALRunScore.LO) | |
| # | |
| # plot the data, add loess curve | |
| ylim <- c(3,6) | |
| plot(ALseason$R ~ ALseason$Year, | |
| ylim = ylim, | |
| main = "American League: runs per team per game, 1901-2012", | |
| xlab = "year", ylab = "runs per game") | |
| # chart tidying | |
| grid() | |
| # loess predicted value line | |
| lines(ALseason$Year, ALRunScore.LO.predict, | |
| lty="solid", col="red", lwd=2) | |
| # | |
| # | |
| # VERSION 2 -- add "span" control to adjust smoothing | |
| # | |
| # references: | |
| # http://princeofslides.blogspot.ca/2011/05/sab-r-metrics-basics-of-loess.html | |
| # http://research.stowers-institute.org/efg/R/Statistics/loess.htm | |
| # | |
| # create new object RunScore.LO for loess model, span=0.25 | |
| ALRunScore.LO.25 <- loess(ALseason$R ~ ALseason$Year, span=0.25) | |
| ALRunScore.LO.25.predict <- predict(ALRunScore.LO.25) | |
| # | |
| ALRunScore.LO.5 <- loess(ALseason$R ~ ALseason$Year, span=0.5) | |
| ALRunScore.LO.5.predict <- predict(ALRunScore.LO.5) | |
| # | |
| # plot the data, add loess curve | |
| ylim <- c(3,6) | |
| plot(ALseason$R ~ ALseason$Year, | |
| ylim = ylim, | |
| main = "American League: runs per team per game, 1901-2012", | |
| xlab = "year", ylab = "runs per game") | |
| # loess predicted value line | |
| lines(ALseason$Year, ALRunScore.LO.predict, lty="solid", col="red", lwd=2) | |
| lines(ALseason$Year, ALRunScore.LO.25.predict, lty="dashed", col="blue", lwd=2) | |
| lines(ALseason$Year, ALRunScore.LO.5.predict, lty="dotdash", col="black", lwd=2) | |
| # chart tidying | |
| legend(1980, 3.5, | |
| c("default", "span=0.25", "span=0.50"), | |
| lty=c("solid", "dashed", "dotdash"), | |
| col=c("red", "blue", "black"), | |
| lwd=c(2, 2, 2)) | |
| grid() | |
| # | |
| # | |
| # | |
| #-N-N-N-N-N-N-N-N-N-N-N-N-N-N | |
| # | |
| # NATIONAL LEAGUE | |
| # | |
| # create new object RunScore.LO for loess model | |
| NLRunScore.LO <- loess(NLseason$R ~ NLseason$Year) | |
| NLRunScore.LO.predict <- predict(NLRunScore.LO) | |
| # | |
| # plot the data, add loess curve | |
| ylim <- c(3,6) | |
| plot(NLseason$R ~ NLseason$Year, | |
| pch=2, col="black", | |
| ylim = ylim, | |
| main = "National League: runs per team per game, 1901-2012", | |
| xlab = "year", ylab = "runs per game") | |
| # loess predicted value line | |
| lines(NLseason$Year, NLRunScore.LO.predict, lty="solid", col="blue", lwd=2) | |
| # chart tidying | |
| grid() | |
| # | |
| # | |
| # VERSION 2 -- add "span" control to adjust smoothing | |
| # | |
| # reference: http://research.stowers-institute.org/efg/R/Statistics/loess.htm | |
| # | |
| # create new object RunScore.LO for loess model | |
| NLRunScore.LO.25 <- loess(NLseason$R ~ NLseason$Year, span=0.25) | |
| NLRunScore.LO.25.predict <- predict(NLRunScore.LO.25) | |
| NLRunScore.LO.5 <- loess(NLseason$R ~ NLseason$Year, span=0.5) | |
| NLRunScore.LO.5.predict <- predict(NLRunScore.LO.5) | |
| # | |
| # plot the data, add loess curve | |
| ylim <- c(3,6) | |
| plot(NLseason$R ~ NLseason$Year, | |
| pch=2, col="black", | |
| ylim = ylim, | |
| main = "National League: runs per team per game, 1901-2012", | |
| xlab = "year", ylab = "runs per game") | |
| # loess predicted value line | |
| lines(NLseason$Year, NLRunScore.LO.predict, lty="solid", col="blue", lwd=2) | |
| lines(NLseason$Year, NLRunScore.LO.25.predict, lty="dashed", col="red", lwd=2) | |
| lines(NLseason$Year, NLRunScore.LO.5.predict, lty="dotdash", col="black", lwd=2) | |
| # chart tidying | |
| legend(1980, 3.5, | |
| c("default", "span=0.25", "span=0.50"), | |
| lty=c("solid", "dashed", "dotdash"), | |
| col=c("blue", "red", "black"), | |
| lwd=c(2, 2, 2)) | |
| grid() | |
| # | |
| # | |
| # | |
| # | |
| # MULTI-PLOT -- MERGING AL AND NL RESULTS | |
| # | |
| # plot individual years as points | |
| ylim <- c(3,6) | |
| # start with AL | |
| plot(ALseason$R ~ ALseason$Year, | |
| type="p", pch=1, col="black", | |
| main = "Runs per team per game, 1901-2012", | |
| ylim = ylim, | |
| xlab = "year", ylab = "runs per game") | |
| # add NL line | |
| points(NLseason$Year, NLseason$R, pch=2, col="blue") | |
| # chart additions | |
| grid() | |
| legend(1900, 6, c("AL", "NL"), pch=c(1, 2), col=c("black", "blue")) | |
| # | |
| # plot individual years as lines | |
| ylim <- c(3,6) | |
| # start with AL line | |
| plot(ALseason$R ~ ALseason$Year, | |
| type="l", lty="solid", col="red", lwd=2, | |
| main = "Runs per team per game, 1901-2012", | |
| ylim = ylim, | |
| xlab = "year", ylab = "runs per game") | |
| # add NL line | |
| lines(NLseason$Year, NLseason$R, lty="solid", col="blue", lwd=2) | |
| # chart additions | |
| grid() | |
| legend(1900, 3.5, c("AL", "NL"), lty=c("solid", "solid"), col=c("red", "blue"), lwd=c(2, 2)) | |
| # | |
| # | |
| # plot loess curves (span=0.25) | |
| ylim <- c(3,6) | |
| # start with AL line | |
| plot(ALRunScore.LO.25.predict ~ ALseason$Year, | |
| type="l", lty="solid", col="red", lwd=2, | |
| main = "Runs per team per game, 1901-2012", | |
| ylim = ylim, | |
| xlab = "year", ylab = "runs per game") | |
| # add NL line | |
| lines(NLseason$Year, NLRunScore.LO.25.predict, lty="dashed", col="blue", lwd=2) | |
| # chart additions | |
| legend(1900, 3.5, | |
| c("AL (span=0.25)", "NL (span=0.25)"), | |
| lty=c("solid", "dashed"), | |
| col=c("red", "blue"), | |
| lwd=c(2, 2)) | |
| grid() | |
| # | |
| # | |
| # plot loess curves (span=0.50) | |
| ylim <- c(3,6) | |
| # start with AL line | |
| plot(ALRunScore.LO.5.predict ~ ALseason$Year, | |
| type="l", lty="solid", col="red", lwd=2, | |
| main = "Runs per team per game, 1901-2012", | |
| ylim = ylim, | |
| xlab = "year", ylab = "runs per game") | |
| # add NL line | |
| lines(NLseason$Year, NLRunScore.LO.5.predict, lty="dashed", col="blue", lwd=2) | |
| # chart additions | |
| legend(1900, 3.5, | |
| c("AL (span=0.50)", "NL (span=0.50)"), | |
| lty=c("solid", "dashed"), | |
| col=c("red", "blue"), | |
| lwd=c(2, 2)) | |
| grid() | |
| # | |
| # | |
| # | |
| # plot multiple loess curves (span=0.50 and 0.25) | |
| ylim <- c(3,6) | |
| # start with AL line | |
| plot(ALRunScore.LO.5.predict ~ ALseason$Year, | |
| type="l", lty="solid", col="red", lwd=2, | |
| main = "Runs per team per game, 1901-2012", | |
| ylim = ylim, | |
| xlab = "year", ylab = "runs per game") | |
| # add NL line | |
| lines(NLseason$Year, NLRunScore.LO.5.predict, lty="solid", col="blue", lwd=2) | |
| # add 0.25 lines | |
| lines(ALseason$Year, ALRunScore.LO.25.predict, lty="dashed", col="red", lwd=2) | |
| lines(NLseason$Year, NLRunScore.LO.25.predict, lty="dashed", col="blue", lwd=2) | |
| # chart additions | |
| legend(1900, 3.5, | |
| c("AL (span=0.50)", "NL (span=0.50)", "AL (span=0.25)", "NL (span=0.25)"), | |
| lty=c("solid", "solid", "dashed", "dashed"), | |
| col=c("red", "blue", "red", "blue"), | |
| lwd=c(2, 2, 2, 2)) | |
| grid() | |
| # | |
| # # # # # # # # # # # # # # # # # # | |
| # | |
| # calculate the difference between the two leagues | |
| # 1. absolute | |
| RunDiff <- (ALseason$R - NLseason$R) | |
| # 2. LOESS span=0.25 | |
| RunDiffLO <- (ALRunScore.LO.25.predict - NLRunScore.LO.25.predict) | |
| # | |
| # plot the LOESS difference | |
| ylim <- c(-1,1) | |
| plot(RunDiffLO ~ ALseason$Year, | |
| type="l", lty="solid", col="red", lwd=2, | |
| main = "Run scoring trend: AL difference from NL, 1901-2012", | |
| ylim = ylim, | |
| xlab = "year", ylab = "runs per game") | |
| # add line at zero | |
| abline(h = 0, lty="dotdash") | |
| grid() | |
| # | |
| # plot each year difference as line, trend as line | |
| ylim <- c(-1,1.5) | |
| plot(RunDiffLO ~ ALseason$Year, | |
| type="l", lty="solid", col="red", lwd=3, | |
| main = "Run scoring trend: AL difference from NL, 1901-2012", | |
| ylim = ylim, | |
| xlab = "year", ylab = "runs per game") | |
| # add RunDiff line | |
| lines(ALseason$Year, RunDiff, lty="solid", col="black", lwd=1) | |
| # add line at zero | |
| abline(h = 0, lty="dotdash") | |
| grid() | |
| # | |
| # | |
| # plot each year difference as bar, trend as line | |
| ylim <- c(-1,1.5) | |
| plot(RunDiff ~ ALseason$Year, | |
| type="h", lty="solid", col="blue", lwd=2, | |
| main = "Run scoring trend: AL difference from NL, 1901-2012", | |
| ylim = ylim, | |
| xlab = "year", ylab = "runs per game") | |
| # add RunDiff line | |
| lines(ALseason$Year, RunDiffLO, lty="solid", col="black", lwd=2) | |
| # add line at zero | |
| abline(h = 0, lty="dotdash") | |
| # chart additions | |
| grid() | |
| legend(1900, 1.5, | |
| c("AL difference from NL: absolute", "AL difference from NL, LOESS (span=0.25)"), | |
| lty=c("solid", "solid"), | |
| col=c("blue", "black"), | |
| lwd=c(2, 2)) | |
| # | |
| # |
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