How does uTorrent pick which Queued Seed torrent(s) to seed?

[UnfairFire]

So here's the scenario:

I have several Queued Seed torrents and I usually upload them one at a time until the ratio is met. But so far I haven't noticed any pattern regarding which torrents get upload priority. It's not by the number of seeders, it's not alphabetical, it's not by "date created"... I'm bit surprised there isn't a mechanism (afaik) that would allow setting the upload order, just like you can set the order in which to download.

So, how DOES uTorrent choose which torrent(s) get priority when there are no active downloads?

[DreadWingKnight]

Combination of ratio and estimated availability currently.