There is a negative bias in the performance points to the extent that 0-1 is usually better than 6-3. It gets better when everyone has 10 fights and the rankings are official, but I believe the negative bias can still work some mischief. I suspect a fighter just starting out who has destroyed 10 cream puffs will outrank a veteran fighting other contenders who is 8-2 in his last 10 fights, because the negative effect of the losses is so large. Maybe Rocco can tell us whether Gerhard Zech is his top ranked heavyweight.
