For an excellent sequence breakdown, check out Paul G's two comments
here. Reviewing it, I had a moment of insight which I posted there, and am reposting here:
One thing that jumped out at me in reading your breakdown are the parallel, then converging tracks of Irv and Carmine, and Richie and Sydney. I think this may be where some people experienced the movie as a bit messy. When the story veers off into the Richie-Sydney subplot, some may find that a distraction from the Protagonist (Irv) story. However as your breakdown indicates, these two subplots play off each other:
* Irv-Carmine: As noted elsewhere, this is a key relationship in driving home the negative impact to Irv of his cons. By becoming friends with Carmine while being forced to play the guy by the FBI, possibly for the first time and certainly in the most impactful way, Irv realizes the pain his cons cause. His confession to Carmine, also as discussed, is a necessary beat for Irv as part of his metamorphosis from huckster to a more honest life.
* Richie-Sydney: As noted elsewhere, Sydney is the physicalization of the sexy life Richie imagines playing with the Big Boys to be. While she doesn’t actively try to seduce him, he allows himself to be seduced, generally by the con-man’s life, and specifically in his attempt to woo Sydney. So his arc is the converse of Irv: Going from a more honest lifestyle to becoming a con-man.
The delicious irony in the story is that in the end, Irv and Sydney pull off the big sting, leaving Richie in the worst status imaginable: No one knows he had anything to do with anything. He is a nobody, exactly opposite his dreams of becoming a Player. Meanwhile one could argue that from an emotional perspective, we wouldn’t feel a sense of positive resolution re Irv’s ‘victory’ had he not gone through the refining fires forced on him by the FBI and specifically confessing to Carmine and experiencing the pain of his betrayal of their friendship.
Once again, the value of doing deep story analysis. I hadn’t made that clear of a connection between the Irv-Carmine / Richie-Sydney subplots, but through this discussion, I see it quite clearly now.