There is a notorious kind of crack called offwidths. Several friends of mine stated, that they were pretty devastated at first when they were not able to do 5.8 offwidths in the valley. Later they learnd, that this was quite common. There has even been an epic film called "Wide Boyz" about two british climbers taking on the hardest american offwidths. My questions are:
What exactly is an offwidth crack?
What makes offwidth hard to climb? Or less subjective: What technique is required ascend an offwidth?