Well Texasranger says it's better to just buy or grow from seed. TR's experience with dividing prairie dropseed has been very poor. I haven't tried it, but considering the rooting habits of prairie grasses, I can see why. I would probably either leave it or chunk it and replace it.
They easily grow to specimen size in 2-3 years from a plug anyway.

Well, much of the center seemed dead this year, and I'll have to dig it up anyhow, so i might as well try to divide it. Anyone else want to chime in?

Yeah, that does happen to me too...I hope not this year, but in the past with a 7 or 8 year old clump. It's the nature of clump grasses.

Then again, you could enjoy a grass fairy-ring!

I was just thinking today might be a good day to burn the top of my dropseed. I think I will..then I can assess how it might look (can't really tell till new sprouts come out).

Edit: It's burnt and boy does it look sad...for a month or two. However, last year I waited too long and scorched new growth on emerging perennials.

Well, my garden helper and I (the two of us women in our 70s) wrestled that grass out and with a hatchet and saw got 4 starts out of it and we just abandoned the rest of it. So we'll see how the starts do. As hard as the job was, it doesn't compare with dividing a huge Miscanthus 'Morning Light' that we started working on that was completely dead in the center. We worked on it yesterday until we were staggering with shovels, splitting maul, hatchet and saw. Still have most of it to do. Hardest gardening job I've ever done.

(And don't ask why we didn't get some young person to help. Ha! Been looking for one for years.)

Update: 3 of the four divisions of the Sporobolus are greening up, and the 4th may have made it too. So, definitely worth it.

Let me know how it does into early summer. I mean if they look good then, they should be golden. Did you take the starts from the edge and discard center (which you said was dead?)

Yes, I took the starts from the edge.