Efficiency Drop for No-Sparge

Here's a question for those who have a known, calculated, and reliable brewhouse efficiency who batch sparge. And also do recipes with the no sparge method.

I'm interested in doing a no sparge just for the fun of it. I'm pretty dialed in right now with my double batch sparge method at around 78% give or take a few percentage points, but I'm wondering where to calculate my expected efficiency drop. I figure I'll cut that down by an additional 15% or so and go with a BE of 65%.

Either way, I'll pick an easy recipe that has a single bittering hop addition so I can scale it after I measure before the boil - maybe a dry stout.

Any suggestions?

I just did one today. I don't really keep track of my efficiency but it did drop according to calculations in BeerSmith. Not really that big a deal as it is to be expected in no-sparge brewing.

15% sounds good if you're calculating prior to doing it. I would just go ahead and do it and see where you end up. Maybe do a style that is "flexible" in its outcome? I did a basic pale ale grain bill (2 row and Munich) and prepped for APA-style hops. Ended up with more of an IIPA in the end so adjusted hops on the fly.

Just my 2 cents.