My latest research done with a junior math major Alex Everett introduces what I call the “Linear Theorem of Baseball.” The Linear Theorem states W% =.000683*(RS – RA) + .50. In a paper to be published, I show that my Linear Theorem and James’ Pythagorean Theorem are both successful predictors of a team’s season winning percentage for the years 1901 to 2013.
The data in the table below provides the actual standings and standings calculated by my Linear Theorem for all games played on or before August 30^{th}, 2014.
Assuming the season ended on Aug 30, these would be the playoff results. In the AL, Baltimore wins the East by either of the two standings. Detroit and Kansas City would be tied by the actual standings and Detroit would win by the Linear Theorem standings. The LA Angels and Oakland would change places with LA winning by the actual standings. The two wild card teams by the actual standings would be Oakland and either Detroit or Kansas City (which ever lost the tiebreaker). By the Linear Theorem the two wild card teams would be the LA Angels and Seattle.
In the NL, the same three teams would be the divisional winners by both standings. In either case San Francisco would be one of the two wild card teams. St Louis would be the second wild card team by the actual standings and Atlanta would be the second wild card team by the Linear Theorem.
Of the two standings, I would choose the standings given by the Linear Theorem to predict the final playoff teams. Looking at the AL East we see that the Yankees had an actual PCT of 0.522 but dropped to a PCT of 0.482 by the Linear Theorem. What can account for this change? This tells me the Yankees have done very well in close games and part of their success can be attributed to their manager. The same argument can be given for Baltimore. The other New York team had a different result. For the Mets the actual PCT of 0.463 increased to 0.490 when applying the Linear Theorem. This reflects negatively on the Mets manager. It turns out in 1run games the Yankees were 2118, Baltimore was 2719, the Mets were 2126. Miami has the best 1run record at 3220 which helps to explain its better PCT by the actual standings.
]]>My current research done with the help of Kevin Faggella, a math major at QU, introduces a new alternative formula to Bill James’ formula to accomplish the same goal. My formula is Expected W% = .000683*(RS – RA) + .500 and is called the Linear Theorem of Baseball. This formula is developed by applying the statistical techniques of linear regression and correlation analysis to the sample of MLB years 19982012. For those interested in learning these important mathematical tools and seeing the derivation of these theorems go to Chapter 5 of Sandlot Stats. In fact, my Expected W% formula would have correctly predicted the fate of the 2005 Washington Nationals. On July 5, 2005 the Washington Nationals were in first place with a record of 5132 having RS = 340 and RA = 340. According to my formula their Expected W% = .000683*(RS – RA) + .500 = .500. This clearly sent a message about how their season would end. In fact, their final record for 2005 was 8181 with RS = 639 and RA = 673.
Let us now look at the midpoint of the 2013 season and use my formula to make predictions on which teams will make the playoffs. Using 90 wins as the milestone for a team to either win their division or become a wild card, this equates to a final record of 9072 and a winning percentage of (90/162) = .556. Using my formula, we have .556 = .000683*(RS – RA) + .5000. Solving we get (RS – RA) = 82 (rounded). Of course, one might choose 95 wins or some other amount instead of 90. Based on the closing records before the 2013 AllStar game and using my formula, I created a table of all the teams whose Expected W% = .000683*(RS – RA) + .500 is now greater than .500. I also included the Dodgers because they finished the first half winning 18 of their last 23 games.
Using this table along with other data, these are my playoff predictions for 2013. First, the division winners are for the ALEast Boston, for the ALCentral Detroit, for the ALWest Oakland, for the NLEast Atlanta, for the NLCentral St Louis, and for NLWest the Dodgers. My two wildcard choices are for the AL Tampa Bay and Baltimore or Texas (a tossup) and for the NL Pittsburgh and Cincinnati. I pick Detroit for the ALConference winner and St. Louis for the NLConference winner. The last time Detroit won a World Series was in 1984 under the leadership of Sparky Anderson. Detroit’s current manager Jim Leyland managed the 2013 AllStar game to win and the AL won. Yes, with the help of home field advantage the Detroit Tigers will win the 2013 World Series. Sadly, I predict my beloved Yankees will be on vacation during the playoffs.
Original Comments:
2 Comment(s):
Dr. Stan said…
Thank you Dennis for your compliment. I just looked back at my posting on July 23 and it seems like all the teams I predicted to be in the playoffs have an excellent chance of making it.I believe that after a certain number of games looking at the difference between runs scored and runs allowed instead of the winloss record can give a better prediction of a team’s final record. My new formula seems to work and can be used at any point in the season. August 18, 2013 07:47:26

Dennis said…
Stan looks like you are spot on with this formula. Very interesting that you found the Dodgers shooting up before most fans or media! August 18, 2013 06:32:43 