You need to know about responsibility games. Those games in the table are the last games before the rank is promoted. For example, the 3rd round of the preliminary tournament of the 2nd Jincheng Professional Weiqi Open Tournament was the last game Qiu Yuran played as a 5p Go player (in group 26), and he rose to 6p after this game, "70" means his average scores reaching 70 (not less than 70 but less than 75), "responsibility game amount" means the amount of the responsibility games whose scores are calculated to get the average scores, and there are 23 responsibility games whose scores are calculated, which he played as a 5p player. Although he needed 24 responsibility games by rights, his average score could have reached 70 even if he had lost the 24th one, and that's why he only needed 23. The total amount of responsibility games can be larger than the amount mentioned above. For example, Qiu Yuran played 29 responsibility games as a 4p Go player. I think there can be a program to calculate the biggest average score when the responsibility game amount needed is guaranteed, but I don't really know its whole operating mechanism.