Each player is on this own in this one and any number can play, within reasonable limits. Before starting play a specific rally route has to be laid out on the scoreboard. Along the route obstacles are set up. The route may be any length, all 20 segments of the board if you like, with obstacles at any position.
Obstacles usually comprise hitting a tough number twice before continuing on the circuit.
As you can see, the route may be made as difficult or easy as you wish and can wander all across the face of the board. However, the finish line is always on the bull, which requires two hits to finish.