system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] What if the events of "The Hobbit" never happen and Gollum still has the One Ring. What would happen with Sauron and the rest of the events of the Lord of the Rings?
gpt
The Ring would abandon Gollum when Sauron began his rise to power- which it did in The Hobbit- but it would be found by an orc or a goblin instead of Bilbo.  The Orc/Goblin would put it on and easily be dominated by Sauron delivering the Ring right to him.  Saruman bows completely to the supremely powerful Sauron.  
Gandalf tries to rally the Elves and the men of Gondor to stand against Sauron.   There are no Hobbits so the Ents never attack Isengard, Saruman's power is not broken.  Theoden is never delivered from Saruman's grasp because Gandalf never becomes Gandalf the White.
Sauron doesn't rush his assault on Gondor and when it does come it is much more devastating.  Minas Tirith is destroyed.  Aragorn, who went directly to Minas Tirith instead of taking the long route through Rohan, is killed.  
Sauron becomes the Dark Lord of Middle Earth.