Purpose: The purpose of this study was to investigate the effect of different positions, velocity and impinging angle of the cue ball on scoring situation in 9-Ball billiard. In addition, the back-propagation neural network with optimization method was used to find the optimal solution in the break. Methods: The subjects were 16 excellent 9-Ball pool players. Experiment was conducted on the right half of the table. The breaking line from the right edge to the central point was equally divided into seven points. Every player broke three times in each of the seven points and usual game breaking point. The subject was requested to break in stop shot way. The procedure was recorded using two synchronized high-speed cameras (120Hz). Kwon 3D motion analysis software was used for data analysis. Chi-Square tests were used for statistical analysis. The significant level was set at α=.05. The structure of neural network used two hidden layers and analyzed by a Matlab program. Results: The scoring rate of the 1st position was significantly greater than that of the 3rd, the 4th, the 5th, the 6th , and the 7th position. Overall, the position that was more closed to the cushion had higher score. In the 1st, the 2nd, the 3rd, and the 4th position, the differences of scores for each hole were significantly different in chi-square test. These results showed that when break in the above four positions, some holes may have higher scores than the other holes. The results of back-propagation neural network and optimization analysis in the1st position showed that the cue ball velocity did not seem to have a main effect on score. Only between the velocity of 9.7-10.5 m/s, the impinging angle toward right can have better score. In other velocity range, the impinging angle slightly toward left can have better results.