Just a note about probabilities. There's actually an 11/36 (30.6%) chance of rolling a specific number, and the chance of a double is 1/6. So the probability of activating the rolled-double ability is 11/216 (5.1%). Even then, it's far from guaranteed that the piece type chosen by that double is able to capture a piece, or that such capture is desirable.
Just a note about probabilities. There's actually an 11/36 (30.6%) chance of rolling a specific number, and the chance of a double is 1/6. So the probability of activating the rolled-double ability is 11/216 (5.1%). Even then, it's far from guaranteed that the piece type chosen by that double is able to capture a piece, or that such capture is desirable.