Figure out whether row/col and select relevant outer edges. Then do an edge loop, then select all the faces containing both selected edge loops and for every second face idea, hopefully be able to get faces as an array, and then just select every second one (which could mess up, so might need to index the array based on someting particular, like start point from selected face). Don't know if any of that is possible yet.
I'm gonna throw a bit of a sissy fit here... I really doubt I'll be able to get any attempt in for this. Friggin work + moving house + partying + poker tournaments + samurai sword fights, they take their toll!
Fair deal...these are workshops not challenges....so I don't worry much if people don't have time to enter Glad you're still thinking about it though...maybe you'll be able to find time for the next one....OR ELSE THE TOASTER GETS IT.