Sufficiency of each parties' contentions is one of the most common issues in patent cases in Delaware. Both sides tend to want to know exactly what the other side plans to argue—ideally before claim construction. That way the parties can construe the terms that actually matter, and have straightforward dispute about whether the accused product and the prior art meets the claim elements.
Beyond that, both parties typically want the other side to be held to what they disclosed in their contentions. The rules generally prohibit a party from disclosing one thing and then arguing something else later, for no reason (although Third Circuit law can be remarkably soft on this point).
Having a reasonable idea …