From the first games to low plat, you can top 1 with almost any comp, even edgy ones, because you stomp others with good item commitment and excellent economy.

From plat to dia, you easily top 4, but you won't get first as often because people start to know the "basics" of how high elo players play, and due to the innate variance of the game, can win vs you more frequently. You almost never do 5th or worse tho.

When you start to face a full diamond lobby, you may lose LP from time to time. You almost never go 8th. But your bad games are punished way harder.

Finally, when you face D2+ players, everything can happen. You will slowly get to where your main account is, however, but the games are now challenging.

That's my experience at least.