Blackhawks searching for root cause of recurring second-period struggles

Blackhawks searching for root cause of recurring second-period struggles

The Blackhawks have played 40 minutes of respectable hockey in most games this season. That's significantly better than zero or 20 minutes, as was often the case last season.But they're still struggling to put together complete 60-minute efforts. Most of the time, it's the middle 20 minutes — the second period — during which they're letting themselves down.They've been outscored 19-12 in second periods, a minus-seven goal differential that's tie…