Confused about PvP spreads on different website

Hello, I've never done PvP before and was looking at some pokemon in my storage. I get confused between stadiumgaming and pvpoke. because I put in my Diggersby as an example. with 15-14-14 and on one website it says this spread is rank 27 but on the other it says the spread is rank 2870 which seems like way to big of a difference. would like help with clearing up the confusion. since one website says they are amazing and the others say they are bad. same happens for my steelix. but my Arcanines spread is the same rank on both websites.

Help appreciated thanks