One of the FallaciousArgument''''''s, and a relative of both AdVerecundiam (argument by authority) and IdontSufferFoolsLikeYou. In this particular fallacy, rather than referring to an allegedly-expert third party, the speaker proclaims ''him/herself'' an expert, and insists that therefore he/she has the final say on all matters pertaining to the subject at hand (and thus wins the argument by default).

Credentials (degrees earned, a C.V., etc.) to support these claims of expertise may or may not be produced. Sometimes the claim of expertise is replaced by a claim of superior intelligence - a refined form of "I'm smarter than you, nyah nyah".

Sometimes, ''two'' parties to an argument will ''both'' proclaim themselves experts - and the argument quickly shifts from the topic at hand to a debate on who has the claim to ''greater'' expertise (under the assumption that this person will then automatically win the original argument).

 A: I've got a master's degree in <foo>
 B: Well, I've got a Ph. D!
 A: But I've got 20 years of industry experience in <foo>
 B: My Ph. D is from CalTech
 A: I submitted a paper on <foo> to the Twenty-Eighth Annual Conference of the 
    Association for <foo>, which was published in the proceedings!
 B: I was the ''chairman'' of that conference.
And so forth. Which sounds rather silly coming from supposed-professionals.

DuelingCredentials is a fallacy for the same reason that AdVerecundiam is a fallacy - being an expert doesn't make you right on all issues. In many fields of study, the only proper way to settle a question is through formal, verifiable research - experiments, theorems and their proofs. Conjecture, even from a Ph. D, is still that - conjecture.

Of course, an expert is more likely to be right on a given topic than a complete layman - if a carpenter argues with a plumber on the correct way to amputate a leg, my money rides on the physician (no matter how handy the carpenter may be with a saw). And if an expert is debating someone who has no clue on the subject (but persists in asserting that EveryoneHasHisOpinion), pulling rank may be useful.  (Unfortunately, some folks are sufficiently narrow-minded that they consider anyone who disagrees with them a layperson by definition).

But in a technical community where most of the participants are familiar with the subject matter at hand (even if not at a Ph.D. level), side-arguments about whose rose smells sweetest are seldom productive. A true expert should be able to win the argument against a (reasonable) non-expert in any case by virtue of logic and reasoning, without resorting to DuelingCredentials.

''DuelingCredentials is an anti-pattern that demonstrates that "credibility" for both sides gets affected by prolonged focus on "credentials".''

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Question : what is the point of this article? 

Answer: It will provide a handy reference the next time a pair of contributors to this Wiki engage in DuelingCredentials.
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