At the earliest around the early 16th century, it is also the time of
Abbas the Great.
That's where I see a problem... Allow me...
1. Early 16th century, the Ottomans had a technological and numerical advantage military wise over the Safavids. The Safavids did not like gunpowder weapons as they did not consider it as courageous. It was the defeat in Chaldiran that convinced the Safavids to adopt it and by the time of Shah Abbas the Great, they started to adopt it in large numbers. The Safavids were militarily no match for the Ottomans in 1514, 1532-1555 and 1578-1590. The latter war was also the period in which the Janissary Corps started to lose their discipline (f u Murad III).
2. By the time of Abbas the Great, the Ottomans are well in control over Anatolia. While the Turkmens were never really happy with the Ottomans overtaxing the land and sending Governors who have little connection to the Turkmens of Anatolia, the advantage of Turkmen tribes control old Beyliks is long gone. Besides, Abbas the Great had success near the Persian border but that was pretty much it. There is a little chance he can go further in to Anatolia and expect success. Like, maybe he can even win a victory but he cannot consolidate Anatolia. He does not have the manpower, the resources for a geography against the Persian military. The unhappy Turkmens are the only advantage he has but they are no match for the Ottoman Army who are very close and based in Rumelia. OTL gains of Eastern Anatolia is the best Abbas the Great could have gotten, maybe even Sivas but that is pretty much it.
But now it is time for my theoretical scenario...
- Ottomans face a new Civil War between Cem and Bayezid in 1481
- Bayezid cannot defeat Cem in Anatolia, but Cem is defeated by local Turkmens who restore their old Beyliks
- The Safavids still rise to power
- They experience rivalry with the Mamluks over Southern and Central Anatolia
- The Mamluks are defeated like the Uzbeks are
- Most of Anatolia is divided in small Beyliks recognizing Ismail Safavi as their nominal overlord
- The situation is like post-Seljuk Anatolia where the Beyliks recognize the authority of the Il Khanate more or less. The further West, the less influence the Safavids have
Even in this scenario, it is pretty much guaranteed the Ottomans will return to Anatolia, will face the Safavids because of it. Considering it took Chaldiran for the Safavids to adopt gunpowder it is likely that the Safavids will still be wiped the floor with and Ismail probably risking death if he moves even further into Anatolia.
