Anyone who watched the original (and superior) iteration of “Star Trek” knows that if someone is going to die on a mission to a planet, he or she is likely to be wearing a red uniform shirt.

True, or not? Something called Significance Magazine begs to differ:

The idea of red-shirted characters being frequently killed in Star Trek: The Original Series has become a pop culture cliché. But is wearing a redshirt in Star Trek as hazardous as it is thought to be? To find out, casualty figures for the Starship Enterprise were compiled using the casualty list provided by Memory Alpha.

Using what is known about Enterprise crew and casualty figures, suppose an Enterprise crew member has been killed. Discarding the 15 unknown casualties, redshirts consist of 60.0% of all fatalities where the uniform color is known; blue and gold uniforms are the remaining 40.0% of casualties. Redshirts are only 52.0% of the entire crew, but 60.0% of casualties, so what is the probability that the latest casualty was wearing a redshirt? The Enterprise often visits Starbases and takes on new crew members, so we assume sampling with replacement. Otherwise, the population size would change every time a crew member is killed.

Significance Magazine uses something called Bayes’ Theorem (of which I am unfamiliar because journalism is the opposite of math) to conclude:

There is a 61.9% chance that any given casualty is wearing a redshirt. This really does not help the insurance premiums of operations, engineering and security personnel. Three departments wear redshirts so it may be worthwhile to take a deeper look at the data to determine if a wearing a redshirt is as hazardous as it appears to be. …

There is a 64.5% chance that any given casualty in a redshirt is a member of security. We can also conclude there is only a 35.5% chance that any casualty in a redshirt is not a member of security. This is in spite of security being only 37.7% of the entire population of redshirts. So what does this mean for red-shirted crew members not in security? Remember, security, operations and engineering wear redshirts. The 15 unknown crew members are not included in this calculation. …

Although Enterprise crew members in redshirts suffer many more casualties than crew members in other uniforms, they suffer fewer casualties than crew members in gold uniforms when the entire population size is considered. Only 10% of the entire redshirt population was lost during the three year run of Star Trek. This is less than the 13.4% of goldshirts, but more than the 5.1% of blueshirts. What is truly hazardous is not wearing a redshirt, but being a member of the security department. The red-shirted members of security were only 20.9% of the entire crew, but there is a 61.9% chance that the next casualty is in a redshirt and 64.5% chance this red-shirted victim is a member of the security department. The remaining redshirts, operations and engineering make up the largest single population, but only have an 8.6% chance of being a casualty.

If I were being an ingrate here I would point out that two Star Trek redshirts, Chief Engineer Scott and communications Lt. Uhura, survived the entire three years, because they were regular cast members. A security guard was not a regular cast member (see? They were expendable!) until “Star Trek: The Next Generation.” Of course, the whole thing falls apart there because red shirts and gold shirts (or “chartreuse” as described by Significance Magazine) were switched in ST:TNG, presumably for aesthetic reasons. The second series certainly didn’t kill red-shirted Captain Picard and Commander Riker. Worf and Chief Engineer Geordi LaForge were switched from red shirts to gold shirts in the second season.

The more pedestrian explanation might be an observation by David Gerrold, who wrote the funniest episode of the first series, “The Trouble with Tribbles.” Gerrold’s The World of Star Trek noted the difference between format and formula, and had a list of the number of episodes, particularly in the third season, that were rewarmed (or “repurposed” in today’s lingo) earlier episodes, or reused plot points thereof. Format: Explore an unexplored planet, where unexpected dangers arise: Formula: Beam down to a strange planet, have the scary being on the planet kill one of the redshirts. Or as one of the comments puts it:

To echo others, but maybe be a little more specific: the set of shirts we should be examining are the ones on landing parties.  The general rule/joke is: “Four people beam down in a landing party: Kirk, Spock, McCoy, and some redshirt.  Guess who’s not coming back?”

By the third season, creator Gene Roddenberry’s attention was wandering since it was obvious that “Star Trek,” which nearly didn’t survive to season three, wasn’t going to survive season four. (And in many instances, a cancellation of the third season might have been considered a mercy killing.) The series had lost some of its creative and producing talent, and it had run out of original story ideas, at least in Gerrold’s view.

And as proof some people have, or did have, too much time on their hands, another comment:

Here’s the thing … Because they were experimenting with things in [“Where No Man Has Gone Before,” TOS’ second pilot that became its third episode], both Mitchell and Kelso [who both died] are wearing beige operations shirts as Helm and Navigation, positions which were previously and subsequently “gold” command positions (at least in TOS). As a result, both were technically “red-shirts”, not gold (since these were not the old style chartreuse-colored uniforms). They also wear assignment patches used for operations in this episode. So the final count of gold and red shirts would be modified depending on whether you assign these deaths by color of shirt only, or whether you take into account their actual duties.

So the redshirt body count undercounts, according to this comment. If you find that illogical, you have company.