Here is the online manual for the JS Fairly Childish compressor:
https://wiki.cockos.com/wiki/index.p...FairlyChildish
It says this about bias:
"The Bias
When this is set low and the threshold set to catch peaks, you get fairly hard ratios of 30:1 (give or take) - and as you lower the threshold, the ratios goes up a LOT - to around 300:1 (give or take). But with the bias set high and the threshold set to just catch the peaks, you get some gentle compression, with the ratio fluctuating from around 1.1 to 3:1. As you lower the threshold, the ratio goes up ... to around the 15:1 mark give or take. "
HTH