I pretty much start mine out the same. Top open, bottom cracked to about the first or second hole on the ash catcher. That's about 1/4, little less.
I monitor with digital probe at grate level and start adjusting the top when it gets creeps up to 200ish, depending on the temp I'm wanting to achieve for the cook.
When it's settled in, the slightest and I mean slightest adjustment can dial it up or take it down 20 degrees or so. Actually pretty cool how little adjustment it takes.
Take pics and good luck!
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