Shellys' so-called unbelievable change of heart spoiler

I am going to address my comments only to the criticism of the last 30 minutes of the film. According to many of the commentators, the ending is “unbelievable.” I think what these viewers are missing is that the movie is not meant to be believable, it is pure myth. Moreover, Bernie does not talk Shelly into having a change of heart. To think that would be to miss the entire point of the Shelly character and of the movie.
It is a credit to the film makers that they do not hit us over the head with it, but in fact, all along, Shelly is not an SOB using his best friend and destroying those who get in his way. In fact, it is the exact opposite: all of Shelly’s actions are designed to help Bernie.
You have to get involved in the back story to work this all out. Recall that Shelly and Bernie have been friends a long time—partners in crime when they were both grifters. We learn that Shelly has had Bernie kneecapped. Natalie expresses horror at this revelation; but Bernie explains that he was addicted to gambling and was in debt to the casinos for more than he could pay. Shelly’s seemingly heartless act has cured Bernie of his disease (“Anytime I think of gambling,” he says, “I just reach down and feel what’s left of my cartilage…and the feeling passes”) and puts him in a position to pay back the debt—thereby saving his life.
Time passes, Bernie’s obligation is up and he wants to move on. Then Bernie “by chance” runs into his son (clearly a bad egg if ever here was one) In one of the most horrible scenes, however, we watch appalled as Shelly proceeds to threaten the life of Mike and his bride and unborn daughter. Indeed, in an unimaginable act of brutality, Shelly viscously kicks the pregnant woman in the stomach, only to reveal the pillow she has been hiding, thereby unmasking the perfidy of the couple, who have intended all along to bilk Bernie. Shelly kneecaps Mikey, which at first seems horrible, but in reality probably puts him off taking on his father again. In other words—it’s the myth of Texas justice—i.e. the illegality of the act is not in question--the jury are to consider only whether or not the SOB had it coming to him.
Natalie starts going out with Bernie; then we find that Shelly has hired her to hustle and romance the poor slob, just to keep him in Vegas. When it seems like his plan has backfired—that the two have really fallen in love with each other—Shelly again commits unspeakable violence, this time to Natalie, which violence, however, only makes her love Bernie more. Convinced now that love has given him luck, he confronts Shelly on the roof top of the Casino. Shelly professes to be unmoved. But then, Bernie goes on to win at craps, aided, as we note, by Shelly’s curious power (which we saw earlier when he jinxes Mike’s crapshoot) of giving the dice the eye, to make them turn up as he wants. We know now--having suspected it in the earlier scene with Mike’s shoot where it is Shelly, not Bernie who clearly turns the tables—that it is really Shelly who is the cooler. Shelly does not need, and has never needed Bernie. Bernie is a loser indeed—but only because of his own weakness of character.
With the power of love behind him, Bernie really does have luck on his side, but it is clear he doubts this luck, as he keeps looking nervously at Shelly who is standing over the final game with this inscrutable look on his face. But Shelly gives Bernie the win, and even takes out one of the real Bad guys (symbolized, as is pretty common, by the young educated Turk with all brains and no heart.)
So are we being asked to believe that Bernie’s rooftop eloquence has finally turned the hard heart of Shelly? Certainly not. Indeed we must see Shelly as the very conscious force that has only ever had one goal—to see Bernie “get everything he deserves.” All of Shelly’s seeming barbarities only help to further the escape of Bernie from his life-long doldrums. Shelly really has been his friend all along—a sort of Machiavellian Genie in the bottle–if you’ll pardon the mixed metaphor.
Shelly does, of course have his own agenda as well. Knowing full well that he, like his singer friend (whom he euthanizes—again it seems villainous, but don’t forget the singer is a drug addict about to be driven out anyway—the story of the lion pride is clear to all the parties.) But Shelly is an old lion, too, and he wants to go out fighting. He knows he is going out—has known it since before the boss and his two hirelings came in the door.
So what we really have in the last portion of the story is not an improbable change of heart, but instead the final move in a craftily constructed, seamless web of altruistic machination, coupled with the heroic/mythic “blaze of glory” theme. The screenwriters are to be given credit that they don’t make this obvious. They make us work for the satisfaction. If the viewer doesn’t put it together we get cheated by what looks like an unlikely turn of events.

Watch it again, and you’ll see what I’m saying is true.