Latest / Matmonim: Daf Yomi by Rabbi David Lapin
Bava Batra 28 Possession: Introduction - חזקת הבתים:פתיחה
For so long as one needs to show proof of ownership, one does not yet have possession. Possession of land occurs when one no longer needs proof of ownership nor permission for occupation.
Source Sheet
The skinny
The skinny isn't ready yet — notes appear once the transcript is processed.