A dartboard hangs properly when the center of the Bulls-eye is 173 cm from the ground. The official casting distance is 237 cm. Many people have trouble adjusting the oche (throwing line) to the right distance. To adjust the oche to the correct distance, you can also measure diagonally from the bull. When measured diagonally, the oche is 293 cm from the center of the Bulls-eye. See the image for clarification.