This SAG Award is a pretty good predictor for the Academy Awards. Only on eight occasions over the past 19 years did the winner of the SAG Award for Best Supporting Actor not win the Academy Award for Best Supporting Actor. This happened in:
1995: Harris (Apollo 13) lost to Spacey (The Usual Suspects)
1998: Duvall (A Civil Action) lost to Coburn (Affliction)
2001: McKellen (The Lord of the Rings: The Fellowship of the Ring) lost to Broadbent (Iris)
2002: Walken (Catch Me If You Can) lost to Cooper (Adaptation)
2005: Giamatti (Cinderella Man) lost to Clooney (Syriana)
2006: Murphy (Dreamgirls) lost to Arkin (Little Miss Sunshine)
2012: Jones (Lincoln) lost to Christoph Waltz (Django Unchained). This is the first time in SAG Award history that the category's eventual Oscar winner went un-nominated by the SAG, and second overall (after Marcia Gay Harden's win for Pollock).