Hi bud, As far as I'm aware the 'season ends draft' is the one with the reverse team standings in place. With the drafts I''m not 100% but I think your team can move up or down 3 places by 'lottery'.
The midseason draft, the one you refer to is decided by the youth training facilities/staff etc. So Dallas it would seem has a pretty good set up there.
and welcome to the boards here

Please don't forget to cast your vote in the MVP section !! And that goes for the rest of you too !!

Best wishes, Nigel