Quote Originally Posted by Parallel Pain
Quintus I think you're talking about Trebia, where the Roman center, after both flanks collapsed, broke the Carthaginian center. But with both Carthaginian flanks now free to pick new targets, there's no way the Roman center could have exploited the hole they created. So before getting surrounded, they marched forward on the double and escaped.
Sounds like what I was thinking of. For some reason I attributed it to Cannae in my mind.