@royaleagle has this down... did you understand? Essentially it a tough concept to initially get your head around, but when you do then you realize you want 2 things to happen... 1 STEEM to go lower and 2 SBD to STEEM RATIO to wide (higher SBD to lower STEEM is the best)...
I will be writing an article about it soon...but royaleagle has it right