Yep, like Bludawg says. Fat cap helps protect from burning and also, having it down keeps the rub and bark intact on the top. Additionally, most of us don't think the rendered fat from the top adds any moisture to large pieces of meat below anyway.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle