This is kind of a food science query: I remember getting up at 7a.m. one morning to start smoking a whole brisket for dinner party, and I kept it on smoke at 270 or so for about 5-6 hours. Then I wrapped it in foil and cooked it (?) 325-350 in the oven. The internal temperature just wouldn't rise to the desired 195 or so until 7pm, and I was even cranking the oven up before. The hoards were hungry and clammoring. It all turned out great, but I wonder to this day: what can make one chunk of meat so resistant to coming up in temperature, while another cut would be wrung dry in 1 tenth the time?