What makes it a standout Western?

Numerous things. Brando is at his most captivating here, but the story is entrancing as well, even though it's more of a slow drama Western than an action/adventure. When it comes, however, the action is quick and realistic.

There are numerous themes running through the long story. One of the major ones is the clash of the misfit with conventional society. Since society is composed of a bunch of conformist misfits, the misfit must learn to conform if s/he wants to fit in and succeed. In other words, if you want to 'make it' in conventional society it's necessary to hide your problematic past & flaws and put on a front of respectability. Dad Longworth has figured this out and he's not about to allow Rio to ruin it for him.

I would like to offer a word of defense for Dad Longworth: Although it was wrong for him to take the money and leave Rio to be captured, one can't help but empathize with him. If he went back for Rio there was a high risk of capture or death. The safest and most promising route was the selfish one. The good thing is that Dad wisely took advantage of this opportunity and made a good life for himself in Monterey. He was obviously sick of his criminal lifestyle and wanted a real life, a real job and real family. He was getting on in years and knew that this may well be his final opportunity, so he took it.

The problem is that one's past always has a way of haunting us or coming back to bite us in the hind end, which is another theme of the film; hence, Rio walks back into Dad's life 5 years later and his American dream is suddenly threatened. Notice Dad's rage when he whips/beats Rio to an inch of his life; he's doing everything in his power to kill the ugly phantoms of his past, which is why he tries to get Rio hung on false charges later in the story.

Another theme is how love is tied to redemption. Both Dad and Rio are criminals, but both desire redemption and a better life. The love of Dad's wife and the Monterey general populace brings this out in Dad, whereas Louisa's love for Rio slowly changes him. Near the end we plainly see that Rio no longer wants to kill Dad, he doesn't even want to see him; all he wants is to run off with his lady love. If Rio remained the same person he was at the beginning of the story "One-Eyed Jacks" wouldn't be half the film it is.

In addition, Dad's love for Katie, his Mexican wife, is what delivered Katie and Louisa "from the beanfields," as Dad puts it.

Love goes hand-in-hand with loyalty or faithfulness. We see this in Rio's likable Mexican sidekick, Chico (Larry Duran).

One of the best qualities of "Jacks" is that it's refreshingly realistic. There's no goofiness, unbelievable one-liners, over-the-top action or excruciatingly dated aspects, except for the opening credits & corresponding score. Thankfully, the rest of the film isn't.

"One-Eyed Jacks" was the obvious precursor to the Spaghetti Western. For instance, the protagonist is a dyed-in-the-wool "cool" anti-hero (like, say, Eastwood). The main difference between "Jacks" and most Spaghetti Westerns, however, is that "Jacks" has a worthwhile story, which can't be said for most Italo-Westerns; also the anti-hero in "One-Eyed Jacks" slowly transforms into a potentially positive member of society.

The film's influence goes well beyond just the Spaghetti Westerns. Take, for instance, Brando's crucifixion-style beating and long restoration. "Conan the Barbarian" (1982) pretty much ripped-off this entire sequence; Arnold Schwarzenegger even admitted to it.

Pina Pellicer does a notable job as Rio's girlfriend Louisa. Spiritually-speaking, she's incredible. Although she commits a foolish error by sleeping with Rio after getting drunk, on a whole she's the epitome of love, virtue and spirituality. Again, this love is the key factor in Rio's metamorphosis.

Unfortunately Pina committed suicide a few years after "Jacks" was released. Thankfully we have this film to remember her beauty and virtue.

"Jacks" was filmed entirely in California with all the coastal sequences photographed on the Monterey Peninsula, including Pebble Beach. This is one of the few Westerns where you'll see the Pacific Ocean (you'll also see it at the beginning of 1954's "Garden of Evil." Other locations include Big Sur and Death Valley.