Yeah no problem.
The DD slider adjusts how quickly/slowly you level up/down.
Placing it at 10 will make you progress/regress extremely quickly. So, for example, let's say you suddenly demoted to Veteran and you wanted to get back to All-Star as fast as possible. The idea would be to max out the DD slider, and assuming you play well, you'd get to All-Star way faster than keeping it at default (5).
Now, for the reverse, let's say you wanted to slow down or stop the rate at which you level up/down. Say again, you're on All-Star and you want to stay there for awhile. This is when you'd zero out the slider. That would lock you in on All-Star.