>>48878040Fire is 2x against Bug, Steel, Grass and Ice
The first 3 are out of the question since they all resists Grass so it has to be Ice
Water is 2x against Fire, Rock and Ground
The first 2 are resisted by Fire
(we could finish here but let's keep going)
Grass is 2x against Water, Rock and Ground
First 2 resisted by Fire
tl;dr yes it's the only way
I believe it also applies to every type chart all the way from gen 1 as well.