... a red herring ... is a clue which makes you come to a wrong conclusion or something which looks like a clue but isn't.
(M. Haddon, the curious incident of the dog in the night-time, Vintage Books, 2003)

What Is Red Herring?

A red herring is an artificial distraction from the essence of the problem. A red herring is a superficial and redundant piece of information that often complicates the formulation and obscurs the nature, of the problem. This could be a valuable device of problem posing that forces the solvers to investigate the problem first, separate what's important from what is not, and focus on the former.

Below are several examples.

What Is Red Herring

On the Difference of Areas
Area of the Union of Two Squares
Circle through the Incenter
Circle through the Incenter And Antiparallels
Circle through the Circumcenter
Inequality with Logarithms
Breaking Chocolate Bars
Circles through the Orthocenter
100 Grasshoppers on a Triangular Board
Simultaneous Diameters in Concurrent Circles
An Inequality from the 2015 Romanian TST
Schur's Inequality
Further Properties of Peculiar Circles
Inequality with Csc And Sin
Area Inequality in Trapezoid
Triangles on HO
From Angle Bisector to 120 degrees Angle
A Case of Divergence
An Inequality for the Cevians through Spieker Point via Brocard Angle
An Inequality In Triangle and Without
Problem 3 from the EGMO2017
Mickey Might Be a Red Herring in the Mickey Mouse Theorem
A Cyclic Inequality from the 6th IMO, 1964
Three Complex Numbers Satisfy Fermat's Identity For Prime Powers
Probability of Random Lines Crossing
Planting Trees in a Row
Two Colors - Three Points

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