Here is a beef rub that is awesome. I smoked two whole chuck rolls each cut into quarters and trimmed, then oiled lightly and rubbed with this recipe. I took each hunk up to 200F and today it all pulled "like buttah" and the taste and color were awesome, way the best I've ever done.
Big Bad Beef Rub
6 coarsely ground black pepper
3 onion powder, run through screen-type strainer
2 ancho chili powder
2 dried mustard
2 garlic powder
1 chipotle powder
Beef rub is different than pork rub. Pork loves sweetness, but beef does not. The best rib rubs have sugar in them, like Meathead's Magic Dust. In addition, a brisket rub needs to be more aggressive than a rib rub because the meat is much thicker.
You can make this recipe days or weeks in advance. Using a teaspoon as the measure makes more than you need for even a large brisket, so you can just put it in a jar or zipper bag for the next brisket.
Same recipe, scaled for 50 pounds of beef:
for 8 large roasts (50#), double the above: (6X original recipe)
ground black pepper
six tablespoons onion powder, sifted through screen-type strainer
ancho chili powder
2 tablespoons chipotle powder