Cool, thanks @blanchy (and @talesfrmthecrypt).

This part made me think of another question...

A player who stays in the PL but stops playing is different: missed matches don't count as zeroes

I assume that sub appearances count... so a player who comes off the bench and scores 1 point (or comes off the bench, gets booked and scores 0) contributes towards the last 4 appearances. i.e. we're not looking at just "last 4 starts".