If chess rank is determined by IQ, then why is not every number 1

The A&A chess set comes in standard tournament size and includes a 20 * 20 (2.25 squares) silicone chess board, a set of quadruple weighted pieces

A&A Tournament Chess Set/ 20''x20'' Foldable Silicone Chess Board / 3.75'' King Height Plastic Quadruple Weighted Classic Staunton Pieces/Storage Bag

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