Why the extra rank on each side in 4 player chess? - Chess Stack Exchange

Why do we have an extra rank (marked with the red lines) on each side in 4 player chess? What could be the possible logic? (screenshot is taken from chess.com)

Fischer random chess - Wikipedia

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How many blunders does an above advanced chess player make? - Quora

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Why the extra rank on each side in 4 player chess? - Chess Stack Exchange

Chess Armory Wooden Chess Set - 17 inch Large Chess Board Sets for Adults and Kids with Extra Queen Pieces & Storage Box : Toys & Games