I had 24 pounds (3 points) cut off packers and I trimmed about 5-6 pounds of fat off them before I rubbed and put ok the smoker. Pulled off smoker at 170, cubed, rubbed, and sauced and back in the smoker. Finished them up and in the fridge for the night. Vacu sealed the next day for buddies rehearsal dinner and I ended up with 8 pounds of burnt ends.
It would help a lot to buy the points trimmed. But here in Michigan that'll cost you about $3 more a pound. Like I said I lost a lot before I even put them on the smoker. And I'm sure you could get different results with different pieces of meat as well. Im thinking My results were high. I'm gonna assume a trimmed brisket will lose roughly 50% on average based on this. But I can guarantee I'll keep track of all the points I smoke now.