1. Surface Area of Axial Wall Height
2. Taper or Convergence of Axial Wall
3. Ratio of Preparation Diameter to Axial Wall Height
4. short and wide teeth
5. Interference with Arc of Rotation
6. 6 degrees
7. wide arc of rotation
8. supplementary features
9. grooves
10. small diameter
11. small radius of curvature
12. better resistance to dislodgement
13. Occlusal Integrity
14. Irregular Surface
15. Occlusal reduction following the anatomic form of the tooth
16. Occluso-gingival health
17. increased gingival wall height
    1. taper
    2. lenght
18. Circumferencial Irregularities
19. Grooves
    1. definite angle
    2. wall perpendicular to the direction of the force
20. Proximal Box
    1. added flare
    2. buccal and lingual wall meet axial wall at 90 degrees
21. Retention
22. Resistance