The top dog would be the half, presumably, being paid the most money. The 'top half' may not be necessarily the one that's available; the Metcalf drama is proof of this.
Honestly, I started making a list to prove my point - but then I realized that I don't care that much about this. Happy to send the list through, but I get the feeling that we're just going to argue more about definitions and I can't be bothered.
I was just interested in some clarity around the prediction terms.