Whether the term 'hotbox' is recent or not, the theory has been around for ever.
Terry Sampson (ace Nighter Promoter from back in the day) had the legend "If You've Only Got 20 Good Records... Play Your Best 20" stuck to the record decks, and he made a point of referring every DJ to it.
I remember Pat Brady and I having a discussion 25+ years ago, where he believed it was nigh on impossible to be a Top DJ and a Collector also. He believed that you had to continuously sell the 'back of the box' tracks to finance the new 'front boxers!'.
It's a reasonable theory, if you're always aiming to be upfront and keep your set 'fresh'... but as a Soul Lover 1st, a Collector 2nd and a DJ 3rd, I've always found it unattractive... even though I'm always adding new tracks to my box, I just can't bear to part with the ones that drop out of the back!
Personally, I'd rather hear a DJ with a good pair of 'ears' and a decent collection to call upon, over someone with a box of so called 'hot' items that are, in reality, only average. The Elipsis (case in point) is about as 'average' a record I've heard played out in ages and the the Stevens & Foster, Jeri track is, at best, a 4 out of 10 tune (IMO).
Still a reasonable approach though, if the intention is to attempt to raise standards.
Sean Hampsey