After a domain drops previously registered through godaddy
 

How long till available? Is it a set time frame or arbitrary based on a formula godaddy has put in place?

Usually 90 days, I believe.
At least it used to be, so...probably.

As little as a day

The grace period is 45 days from the renewal date. If there are multiple back orders, it goes to auction, otherwise it goes back into the available pool.

I will let you know... does search inquiries add to that grace period? More bluntly, does godaddy watch interest on domains through programming and then keep the good ones?

It's possible but I doubt it. Typically interest is gauged by the amount of back orders on it, Godaddy makes money off the auctions.

Yes, they also have backorders on domains and they will register the good ones themselves and try to sell it to you for xxx-xxxx. Grace period or not.

I've had this happen twice.

Not 100% sure but I think that godaddy renew each domain at least for one year and put it on auction.At least it happen with about 50 domains that was expired in my account.

Go to whois.sc > enter in domain name > click registration and tell me when the expiration date is and what the registrar status says, and I'll tell you.