Chapter 5, Problem 23E

Six teams $\left(A,B,C,D,E,\text{and}F\right)$ are entered in a softball tournament. The top two seeded teams $\left(A\text{and}B\right)$ have to play only three games; the other teams have to play four games each. The tournament pairings are $A$ plays against $C$, $E$, and $F$; $B$ plays against $C$, $D$, and $F$; $C$ plays against every team except $F$; $D$ plays against every team except $A$; $E$ plays against every team except $B$; and $F$ plays against every team except $C$. Draw a graph that models the tournament.