University of Minnesota, Twin Cities School of Statistics
This web page implements a playoff probability calculator. Given assumptions about the probabilities for single games, it calculates probabilities for a 5 or 7 game series.
To check out what it does, just click the submit
button below.
Ignore everything but the last six lines, which will look something like
Rweb:> cat("currently,", n1, w1, n2, w2, "\n") currently, Yankees 2 Twins 1 Rweb:> cat("probability", n1, "win series:", p1total, "\n") probability Yankees win series: 0.7525 Rweb:> cat("probability", n2, "win series:", 1 - p1total, "\n") probability Twins win series: 0.2475
To modify what it does, look at the section on modifying the calculation below.
The whole calculation is determined by 5 numbers, which are assigned in the statements at the top of the web form and which you can edit.
ngame <- 7 # number of games in the series w1 <- 0 # number of wins, team 1 w2 <- 1 # number of wins, team 2 p1home <- 0.55 # probability of team 1 win at home p1road <- 0.45 # probability of team 1 win on road
The meaning of these numbers is as follows.
ngame
is the number of games in the whole series
(including games already played), right now only 5 or 7 is allowed.
w1
is the number of wins for team 1 in the games
already played. Team 1 is the team with home field advantage in the series
(the team at home in the first game).
w2
is the number of wins for team 2 in the games
already played.
p1home
is the probability of team 1 winning a game
at home. The default (0.55
) is about right for two evenly
matched baseball teams (the home field/court advantage is much higher
in basketball).
p1road
is the probability of team 1 winning a game
on the road. The default (0.45
) is about right for two evenly
matched baseball teams (the home field/court advantage is much higher
Basically, your opinion only enters the two numbers p1home
and p1road
. If you don't believe the teams are evenly matched,
change these numbers and see what happens.
You can also edit the team names, but this doesn't affect any calculated numbers.
n1 <- "Angels" # name of team 1 n2 <- "Giants" # name of team 2