It looks like I was right. I blogged about this before, but this really slam dunks the case I was trying to make in a much, much shorter format.
I'd also like to point out the disproportionate loss of women of color from that map. Every season, you lose at least one female character, usually the non-white female character. They tried to compensate, it seems, by putting in two new female characters in, but one of them always leaves and the others are now all white.
The issue of women on this show is a sore one for me. Every season has, in a list of 11-13 central characters, only 4 female characters AT MOST. Of those four, only two have been around since season one, if you fudge the matter and count Ali Larter as being continuous even though her characters have not been. That's a serious imbalance before you begin to consider how marginalized the women in this list are. The three remaining in the fourth season play the very definite roles of maiden, mother, crone, too. Which helps immensely, let me tell you.
Someone remind me why I watch this again?