Partial Anglers balls...

Having read the question properly this time....

1. Keep XXXX, test AAAA - BBBB
2. If balanced then one of the Xs -- easy.
3. Else, keep ABB and test AAB and XAB
4. If balanced it's one of the kept three and testing B-B will give you the odd one out (balanced, then A, else the heavy/lighter of the two, as determined by 1).
5. If still unbalanced in the same direction, then the odd one is one of AA (left) and B (right) and can be determined as in 4.
6. Otherwise it is one of the swapped A and B -- balancing one with X will determine which.

Honestly

B

Posted By: Basil Wrathbone, Jan 27, 13:20:38