In your hand you have 9,10,10,J, card turned up is a J, count would be 16, right? Explain why one could not use as a pair, J & J, to count as 2 or 18 for the whole hand.

Double Double Run

The J+J is counted as two points, but that is only part of the 16.

You really have 4 runs of 3 (9-10-J) without using the same cards in any ONE of the runs. And two pair. 4x4=12+4=16