Thanks for bumping this thread, Bogey, so we can get ready for 1946 come Sunday.
I would consider Teresa Wright a lead in BEST YEARS alongside Dana Andrews and Fredric March, with everyone else supporting, but it's not an easy call.
Don't know if anyone else will be nominating performances from THREE STRANGERS, but I would regard Geraldine Fitzgerald, Sydney Greenstreet, and Peter Lorre all as leads.
Joseph Cotten in DUEL IN THE SUN seems like a lead to me, along with Jennifer Jones and ColumboFan's darling Greg, rather than a supporting actor like Charles Bickford, Lionel Barrymore, Butterfly McQueen, etc.
Then there's Lizabeth Scott, who probably has more screen time in THE STRANGE LOVE OF MARTHA IVERS than Barbara Stanwyck, which may suggest that she is a lead like Barbara and Van Heflin.
I'll put Jane Wyman in the lead category where Oscar placed her, although this takes away what would be an easy win for her in the supporting category.
Using the year of initial release completely changes my choices for 1946. If confined to the Oscar ballot, I'd easily pick Laurence Olivier for HENRY V and Celia Johnson for BRIEF ENCOUNTER. But now they've already competed in earlier years. I