I was thinking about the fact that Luffy often fights the 4th strongest of a crew or organization before facing the strongest one. Meanwhile Zoro and Sanji fight the 2nd and 3rd strongest member respectively.
An example of that would be:
Crocodile defeated by Luffy – Mr.1 defeated by Zoro – Mr.2 defeated by Sanji – Mr.3 defeated by Luffy
Lucci defeated by Luffy – Kaku defeated by Zoro – Jabra defeated by Sanji – Blueno defeated by Luffy
This generally happens when the Straw Hats fight against a big organization or crew.
Another strong point to this theory is this:
90% of the time that Luffy says he will beat someone, he always defeat that character. Examples like Crocodile, Doflamingo, Katakuri, Lucci, Moria etc.
Finally I would like to extend on this theory with (I think) a foreshadow of how Luffy will defeat Jack. Like we all know Luffy has learned Advance Armament Haki to be able to defeat Kaido.
I think Luffy will test this new haki on Jack and he will defeat him exactly like Rayleigh defeated the elephant when he was training Luffy.
So that’s it. What do you think?
*Theory by Rozava