Figure 4. The visible evaluation model of the tactical benefit of the second to fourth strokes in the receiving round. The median tactical frequency and scoring rate for the tactics of the second to fourth strokes are 0.011 and 0.450, respectively. Therefore, the tactical benefit value ranges of the four areas are (0.056, 5]; (0, 0.056]; [-0.056, 0) and [-5, -0.056), respectively.