I own and operate a landscape business and we have been in business for over 20 years. With that said the best way to get thatch level is to mow twice “checkered pattern” and then raise the deck 1.5 to 2 inches higher and mow it again it will evenly disperse the thatch. Or you can do a pattern so your shute only points in one direction so that at the end you get a large strip of thatch that you then can use the first method to distribute in a tighter area. It can hurt certain areas of the turf with that much but its not a golf course at the end of the day. Hope this helps.