Yeah, I've gotten higher numbers when I either fly sparge or when I really take proper measurements for strike water used, first runnings volume, strike water needed/used, etc.
I'm basically leaving sugar in the brewery by being a bit lazy. Sure, I could fly sparge (but it takes too long!) or actually use math, but it's more relaxing to me to just grab all the sugars I feel like grabbing and make volume adjustments in the boil kettle. If I end up with more or less beer, so be it! Grain is cheap, so high efficiency is not a priority. Shaving an hour or two off the brew day is a priority!