Pat and Tiffany score a 5 on their dance routine (and the Eagles beat the Cowboys), helping Pat Sr. win all of his money back from Randy. Pat confesses he knew Tiffany wrote the letter from "Nikki" and writes her one of his own proclaiming his love for her. They kiss and are later shown happy, hanging out with Pat's family.
After being released from a mental institution, Pat (Bradley Cooper) is determined to win back his (ex) wife Nikki's heart. Pat was first put in the institution after assaulting the man his wife was having an affair with. She has a restraining order against him because of his violent temper, so he cannot directly contact her. However, through a mutual friend of Pat and Nikki's, Pat is introduced to Tiffany (Jennifer Lawrence) who has her own mental issues stemming from the death of her husband. She is known around town as very promiscuous following her husbands death, but decides she wants to change that. Pat asks Tiffany to deliver a letter to Nikki for him. She agrees, but only if Pat helps her with a dance routine for an upcoming competition. He decides this is fair and begins practicing the routine with her. Eventually Tiffany gives Pat a letter back from Nikki, saying that she is encouraged by the changes in him but isn't ready to meet yet. Tiffany convinces Pat the best way to convince Nikki he has truly changed is to keep helping her with her dance and have Nikki watch them at the competition.
In the meantime, Pat's father Pat Sr. (Robery De Niro) has been losing bets on Eagles games and blames Pat for not being around and messing up the Eagles "juju". He loses all the money he had saved for his restaurant following a game Pat was ejected from for fighting. The money is lost to friend, and Cowboys fan, Randy (Paul Herman). Pat Sr. blames Tiffany for this because of all the time she has been spending with Pat. Tiffany points out that whenever she is with Pat during an Eagles (or Phillies) game, the Philadelphia team wins. Pat Sr. considers this for a moment, then changes his tune on Tiffany, who in turn proposes a "double or nothing" bet with Randy to help Pat Sr. get his money back. The two sides eventually agree on a bet where Pat Sr. puts his bookie business up against the possibility of earning all of his money back. The bet hinges on two outcomes: the Eagles beating the Cowboys and Pat and Tiffany's dance routine earning an average score of 5.0 or better (out of 10) at the upcoming dance competition.
At the competition, the dancers warming up are very, very good, making everyone a bit nervous. Tiffany sees that Nikki is there and freaks out. She goes to the bar and starts drinking vodka and almost falls back into her promiscuous ways with a man at the bar before Pat saves her. Right before they go on stage, we learn the Eagles beat the Cowboys. After their hot and heavy routine, the pair score an average of exactly 5.0, winning the bet for Pat Sr. Pat celebrates by going and intimately talking with Nikki. This devastates Tiffany, as she has fallen in love with Pat. She runs out of the competition without saying a word. Pat Sr. tells Pat what happened, and he chases after her. He confesses he figured out a week before the Tiffany actually wrote the letter to him, not Nikki. He went over to Nikki to tell her that he is finally over her. He hands Tiffany another letter. This one is for her and consists of Pat confessing his love for Tiffany. They kiss and shown at a later time acting like a normal, happy couple while watching an Eagles game with Pat's family.