So this round robin can only use the fifth power of 2, which is 32 positions.
Bypass method:
25 people, 32 positions, and 7 positions are vacant.
① Number 32 bits according to 1~32, and take out 7 blank numbers. The remaining 25 numbers were drawn by 25 athletes.
Note: The number of spaces should be evenly distributed in the upper and lower parts, where 1~ 16 is the upper part and 17~32 is the lower part. Therefore, there are seven numbers: 2,5, 12, 15,18,21,3 1.
② Pairing of 32 numbers with single and double numbers. In this way, the empty pairs are 1, 6, 1 1, 16, 17, 22, 32, and their first round is bye.
So the first round is 32 16, followed by 16 into 8, 8 into 4, 4 into 2, the champion.