I just did a brisket flat (but a nice thick one with a nice thick fat cap), choice, from Sam's Club. It was a little over 6 lbs, so I anticipated about 9 1/2 hours at 225. At 160 degrees, 7 1/2 hours in, I double wrapped it in heavy foil and put in the oven at 225 to finish. At 9 1/2 hours, right on schedule, it hit 190 and I turned it off and kept it warm (the temp went briefly to 192, but then fell off to 176 before serving about an hour later). The foil contained about 1/2 inch of fat, and the lower part of the brisket was a little dry and a little tough. Flavor was great. Any thoughts on how to get a brisket tender throughout? Should I have foiled it sooner? Thanks!