Lights down positioning

So one thing I've noticed while watching old clips of Millionaire is that the way they dim the lights down has been through a few different changes. Here's the examples:




^ The lights down effect was similar to what they used later in the series, although they were slightly positioned differently, and the lights dimmed down quicker as well.



^ The lights down effect kinda traveled in different locations before all the lights ended in the same locating that they do when they officially dim down. 




^ The lights don't really move all that much compared to the first two effects, and dim down a bit slower. They were also positioned almost the same way as a good majority of the syndicated millionaire episodes with Meredith.



^ The front 2 lights start pretty high and move quite a ways down before dimming. This was also the case in the first season of the syndicated run with meredith.

I honestly wonder if there was any reasoning why they changed how the lights dimmed, or if they just randomly programmed it without thinking about it. I like the 2nd lights down effect that was used from late 1999 until February of 2000, but the only thing that kills it is those d**n stairs being an eyesore with the lights still being lit in them.