This is a game for two players (Blue=Ann and Red=Beth), which are medical doctors. The circle represent villages on an island, and the sizes represent number of villagers---1000 or 2000 or 3000. The villages are connected by roads as shown. Crossing of roads are bridges and not intersections---you cannot switch roads there.
The players are supposed to select one village as their location by clicking on the circle. Everybody on the island sees a doctor on average once a year, and people always go to the doctor closest to them (in terms of number of roads they have to travel). In case of a tie, the person would choose randomly, so each doctor could expect "half a patient". Both doctors want to have as many patients as possible. After each click, the colored parts of the cities indicate those people seeing the corresponding doctor.
Click the button "sim You|Comp" to play against the computer. Or click the other button "seq1 Ann---Beth" if you want to place first Ann's location and then Beth's location. Then click the villages. The payoff shown below is the expected number of patients per year in thousands. If the game is over, you have to click the button again before selecting the village(s).