Why isnt WVU ranked higher with 3 top 10 wins?

WVU is 13-4, with wins against #2 Iowa State, #3 Gonzaga, #7 Kansas @ Kansas, and #24 Arizona.

Illinois - 13-5 - ranked 17th, only ranked wins over a #19 and a #9.

Wisconsin - 15-3, ranked #18, only has one ranked win, over a #9.

Michigan - 13-4, zero top 10 wins and only two ranked wins.

Maybe im just not understanding how the ranking system works but these dont seem right. Hopefully you all can provide some insight.