How is a coin toss fair?

you can actually see when the heads/tails when the person grabs the coin when it is toss. So if you saw tails when they grabbed it call heads because thats the back of the coin that will be on the hand. so do you guys think they should just make some other way to make it fair?
Update: no i meant like when the ref tosses it and he tells us which one we want not just two people
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