HI, I'm assuming you are on a gas grill.
On page 21 Steven talks about heat control.
The recipes that make use of direct grilling include in the set-up instructions testing the grill for high heat. For instance HTG fish filets starting on page 295 includes in the instructions, setting up the grill on page 296 picture #3 test for high heat.
Using a multi zone cooking surface most things start over high to sear and carmelize the can be moved to a cooler zone to finish or moved if they flare up and start to burn.
All equipment is different. Your grill cooks differently depending on outside temps and the wind. You just have to adjust and learn. Fortunately, even the failures can be mighty tasty!
I'm sure some of the other nutcases that prowl and lurk around here will chime in with different points of view and other hard earned personal tips.
I don't think a week goes by without all of us learning something new or a different way of doing a dish or technique.
Please, register and join us, (if you dare!)