You asked
Best camera for the sigma 70 200mm f 2 8 dg os hsm sports?
The Sigma 70-200mm f/2.8 is at its best on full frame, where it frames as marked. For a sensible everyday pairing, I'd go with the Nikon D750 or the Canon EOS 6D Mark II. Both are full frame, so you get the lens's full 70-200mm reach.
If you mostly shoot sport from the sideline, look at the Nikon D500. On its APS-C sensor the lens reaches like 105-300mm on full frame, which helps when you're further away. The Canon EOS 7D Mark II does the same job on the Canon side.
For more on how much reach you need, see reach in wildlife and sport.
Written by Claude from this site's pages.