There's no change at the top of this week's ESPN Stats and Info softball conference power rankings, with the Pac-10 once again claiming the No. 1 spot. The top conference for the fourth week in a row, the Pac-10 earned its best average RPI of the season (19.875).

The Big 12, Pac-10 and SEC each have three teams in the RPI's top 10, but the Big 12 and Pac-10 have a considerable lead over the SEC in our rankings. Why is this? As has been the case all year, It is because seven of eight Pac-10 teams are ranked in the top 20 of the RPI, and while the Big 12 doesn't have as many teams in the top 20, it doesn't have a team ranked lower than No. 66 Iowa State.

The SEC is hurt by having two teams outside of the top 100 (No. 111 Arkansas and No. 158 Ole Miss). Despite its RPI average being significantly worse than those of the Pac-10 and Big 12, it has five teams in the top 20, and seven teams in the top 30. If you were to make it an eight team league (like the Pac-10) by eliminating its bottom three teams, its average RPI would improve to 21.375, which would make it the second best conference in this week's rankings. Obviously all conferences would look better if you chose to ignore their bottom teams, but I'm making this point to illustrate the fact that there's a good chance we could see just as many, if not more, SEC teams as Pac-10 and Big 12 teams advance in the NCAA tournament in a few weeks.

Conference (RPI Average)

1. Pac-10 (19.875)
2. Big 12 (23.5)
3. SEC (47)
4. Big Ten (58.8182)
5. ACC (63.875)
6. C-USA (83.6667)
7. Sun Belt (89.2222)
8. MWC (98)
9. Big East (105.0769)
10. Big West (113.625)
11. A-Sun (128.6364)
12. WAC (130.125)
13. MVC (141.1)
14. Southland (141.2727)
15. MAC (146.25)
16. Horizon (150.5556)
17. Southern (151.5556)
18. A-10 (165.3636)
19. Big South (169)
20. Ohio Valley (169.9091)
21. Colonial (173.5)
22. A-East (178.1429)
23. Northeast (193.3636)
24. Ivy (199)
25. Summit (199.6667)
26. P-Coast (215.6667)
27. Patriot (226.5)
28. MEAC (247.7273)
29. SWAC (267.8)