As fans celebrate and detractors deride, baseball is a sport ridden with superstition. Playing 162 games per season will do that, leading to all manner of lucky hats (bats, chew tins, gloves, you name it), pregame rituals, and many other entreaties to the world of the magical. To make matters worse (if you're a believer in this sort of thing), your opponents aren't empty-handed either. You might be trying to placate the Lords of Batting Average, but the player on the mound answers to the Greek God of Strike Outs, and he's at total cross purposes with you.

This is the background needed to begin to understand why tonight, as the World Series begins between the St. Louis Cardinals and the Texas Rangers, the field will probably be full of men who are wearing what can best be perhaps described as magical necklaces. Or, if you're the geeky type, call them +5 Amulets of Baseball Enhancement.

Over the last several years, many major league players have been spotted wearing these bulky metal necklaces during games. Their symbolism isn't religious. They feature no cross, no star of David. Instead, these necklaces supposedly help players perform better by easing fatigue and shortening recovery time. The secret to these supposed benefits: titanium nanoparticles that help the body's own energy flow more readily.

As we'll see, there's zero biological basis for any of these claims (as we'll discuss at length). That does not mean, however, that there's no benefit to wearing these things. The placebo effect is incredibly powerful, and the psychology of sports performance is a very complex beast. And let's face it: if you were being paid anywhere from $80,000 to $18,000,000 per year to swing the ash (or maple) stick, you might not think twice about plopping down anywhere from $35 to several hundred dollars on something that, in short, can't hurt. And if it gives you an edge? So much the better.

The current craze for sportswear laden with nanoparticles is being driven by a company called Phiten, which has an impressive collection of professional athletes endorsing its products. Those products include necklaces, bracelets, magnetic tape, clothing... even shampoo and bedding. They are said to be permeated with nanoscopic titanium (or gold) particles. What you won't find on the company's US website is any mention of what all that metal is supposed to do.

Fortunately, the Phiten sites in other countries and a YouTube video spell it out. The material is "scientifically proven to provide almost instantaneous relief and restore flexibility" because it can "restore the energy flow, or natural bioelectric current, by restabilizing the flow." The products "emit energy, improving bioelectric current at the cellular level—blood cells carry more oxygen, muscle cells fire with more intensity." All of that means Phiten products will "increase performance, lessen fatigue, [and] reduce recovery time."

No, that won't actually happen

Can this possibly work? In a word, no. Having metal near or in contact with your skin isn't going to change the flow of any energy unless there happens to be electrified wires hooked up to that metal. It isn't going to work through magnetism, either (although very similar claims were made about magnetic bracelets). Titanium and gold aren't magnetic. And, even if they were, they'd be too weak. Even bracelets that are permanently magnetized tend to only produce fields of a hundred milliTesla at the point of contact. There is a technique called transcranial magnetic stimulation in which magnetic fields alter the activity of the nervous system, but it requires fields of a Tesla or more. (For context, the Earth's magnetic field is about 10-5 Tesla.)

Even if any of that made sense, there's no indication that the human body has any sort of "energy flow." Acupuncture supposedly works through the same principles, but carefully controlled studies have shown that it doesn't matter where you place the needles, even though their placement is supposedly dictated by the routes that energy flows through the body. Researchers have also generated fake needles that don't puncture the skin—they work, too.

But, despite all this, acupuncture does work. For a variety of conditions, like pain and nausea, acupuncture ("real" or sham) provides relief.

So, in sum: there's no evidence that the body has any sort of energy flow (much less one that can influence the carrying capacity of red blood cells). There is an obvious way in which it transmits energy—nerve impulses—but they are only influenced by electrical currents or strong magnetic fields. The Phiten bracelets provide neither. So there's no biologically plausible mechanism by which these products can directly influence the body.

Yet, it's possible that they work. How can that be?

Placebo doesn't actually mean fake

How could something with no obvious biological effect actually have some effect on a biological organism? Welcome to the strange world of the placebo. Most people are probably familiar with placebo pills, which are commonly used as a control in drug trials. Those trials, however, often reveal that a placebo will lead to improvement in self-reported symptoms. These pills can also, through what's called the "nocebo effect," produce just as many annoying side effects as a real drug.

How does this work? Recent research indicates that, with suitable priming, placebos can lead to the activation signaling pathways that our bodies normally use to control things like, for example, sensitivity to pain. So, a placebo pain-relief pill might rely on the endorphin signaling pathway, which is also targeted by morphine, or can trigger activity from the body's cannabinoid pathways. For things other than pain, there's evidence that a variety of other signaling systems can be activated.

But placebos aren't just limited to pills, as the acupuncture results imply; physical processes can trigger the effect as well. In fact, it's possible to do an entire placebo surgery. In the case of an arthroscopic knee surgery, the physicians create skin incisions and move equipment around, but never actually place any hardware inside the joint. No real surprise that, for osteoarthritis, this works just as well as actually having the knee joint cleaned out a bit.

The most significant debate about placebos in the science and medical community is probably about their ethics. Is it appropriate, for example, to include a placebo group for a brain surgery trial? Would having full, informed consent about a clinical trial include disclosure of placebo use? Would it really matter?

(The answer to that question is "probably not." A few trials have suggested that telling people they're getting an inactive pill that is known to be effective for no obvious reason can still generate a placebo effect.)

All of which is a long-winded way of saying that we don't know the full extent of the placebo effect, but there's every reason to believe that it could be activated by something physical, such as a bracelet or necklace that promises to improve your activity level and decrease your fatigue. (Just don't expect red blood cells to necessarily be the things doing the responding, as Phiten claims.)

It may be all in your brain

But there's a chance that something beyond the placebo effect is also at play. Performance in sports is profoundly affected by a player's state of mind, which is why players and teams tend to have rituals and talismans that are thought to bring good luck in various forms. There's even research out there that suggests a team's uniform color may have a profound effect on their winning percentage; in UK football, teams with red jerseys tended to win games and championships at rates above the expected average (there's apparently a hierarchy of colors, with red > white > yellow). Part of that may come through the effect of the uniform color on goalkeepers when penalties are taken.

These studies, however, are not without their detractors. Red and black uniforms have been linked to aggression, but the effect was not present in one of the most aggressive sports around, ice hockey. Another study that apparently found blue uniforms to be a benefit in judo was later criticized for ignoring confounding factors that eliminated the effect.

So, overall, the evidence for a uniform color effect is a bit mixed. Still, it's quite possible that things like the Phiten necklaces have a psychological impact on those wearing them beyond the placebo effect, one that leads to improved performances.

What we do know is that there is clearly no science behind the claims made by Phiten itself. But that doesn't mean its products have no effect on performance—and there seems to be some science that backs that up. And, if nothing else, having a brightly colored necklace distracting opponents at key moments can't really hurt.