Consider a pool table of length one. An 8-ball is thrown such that the likelihood of its stopping point is uniform across the entire table (i.e. the table is perfectly level). The location of the 8-ball is recorded, but not known to the observer. Subsequent balls are thrown one at a time and all that is reported is whether the ball stopped to the left or right of the 8-ball. Given only this information, what is the position of the 8-ball? How does the estimate change as more balls are thrown and recorded? You can run the app from RStudio’s shinyapps.io service at jbryer.shinyapps.io/BayesBilliards. The Shiny App is included in the IS606 package on Github and can be run, once installed, using the IS606::shiny_demo('BayesBilliards') function. Or, run the app directly from Github using the shiny::runGitHub('IS606', 'jbryer', subdir='inst/shiny/BayesBilliards') function. Source code is located here: https://github.com/jbryer/IS606/tree/master/inst/shiny/BayesBilliards