Tell us about yourself!
The baffle directs the smoke coming from the firebox in the bottom right to the left side of the smoker, then enters the smoking chamber and exits the chimney on the right. Look at the diagram on step 8 and you can see the baffle plate in yellow.
In the build, he built a floor, called a baffle, into the smoker that channels the smoke coming out of the firebox on the right to the left of the boiler. The smoke then moves from the left side over the meat to the chimneys. Look at the diagram on step 8, and you see the baffle in yellow.