The conception: When partner leads a suit against a suit contract, you always play high-low from a doubleton.
The truth: If partner leads the A of a suit, then you signal high-low (unless you hold Qx*), but your signal is NOT a count signal. The reason you play high-low is to show attitude. With a doubleton, you want partner to continue that suit. You would also want partner to continue if you hold the Q of the suit so from Q82 you would play the 8 and then the 2 playing standar
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