Status Updates From Advance and Destroy: Patton...

The Germans probably possessed enough combat power around Bastogne to take the town by sheer weight but all the attacks had been piecemeal permitting the light 101st airborne & key attachments such as 10th armored to repeatedly react at critical sectors to prevent a significant breakthrough against a superior armor heavy force.

To be fair (to and Ike and Bradley and Patton...) based on how Twelth Army Group was receiving information from the front on 16-17 December, the situation looked like piecemeal efforts to kick-start small scale attacks, possibly spoilers for the US army's own offensive plans.