You see, that's what I've based my heavily-researched thesis on. From my understanding back in those days there was a clear class divide when it came to Blue Peter/Magp (and, I won't lie, I only vaguely understand what Magpie was, something to do with talk radio nutjob Tommy Boyd right?). And in my youthful days of the late 80s/early 90s, CBBC seemed a lot... worthier. CITV was all bright colours and people being splatted with cream pies and Knightmare with that beardy dude haunting my darkest dreams for the next two decades as he cackled over graphics of the children competing's faces turning to skulls and Julia Sawahalahala being a solid 7 on Press Gang. CBBC was just, like, lots of TV shows that had the faint aroma of Enid Blyton around them. And The Movie Game,which is as an obscure a reference as you'll ever see on this website.
In the process of researching this answer (read: trying to remember what The Movie Game was called), I found out that the 1980 series of Screen Test was won by Jan Pinkava, director of Ratatouille.