Shared credits
Thayer David averages 6.37, John Karlen averages 6.03. Apart that suggests 6.20; together they average 5.85, a lift of −0.35.
Lift is the average of their films together minus the mean of their two career averages.
Dot size shows IMDb votes; lines are rolling five-film averages. Films with fewer than 1,000 votes are left out.
| House of Dark Shadows | 1970 | 6.3 | 3,847 | as Professor T. Eliot Stokes | as Willie Loomis |
| Night of Dark Shadows | 1971 | 5.4 | 2,037 | as Rev. Strack | as Alex Jenkins |
