winning the dice roll means you have to go first?

Random question about something I've just encountered. I was informed that if you win the dice off / random decider that you have to go first... is this correct as surely the winner of the roll off should get to pick first or second as one may have more benefit to them? example being a rush deck wanting second for Dmg quicker.

Is this correct and if it is / is not can someone provide me with a link to back it up so I can have it handy just in case.

If you win the dice roll/coin flip/whatever, you go 1st.

The rules say you have to determine who goes first randomly. Giving someone a choice is not random. If you win the roll, you go first. That's the accepted method.

And that is exactly why it's random, going first or second can be an advantage.

Yeah, you're "locked" in to go first when you win.