Double Batch Sparge vs. Single Batch Sparge

Wondering if I can get my efficiency higher if I switch to a single. I know there's lots of variables but am wondering what everyone thinks. Thanks!

I'm going to try some experiments with my house brew I keep on hand all the time.so far I have been doing double batch sparging and achieving around 70 percent efficiency.

I just brewed a batch with a 14 lb grain bill and found that the sparge batches didn't even cover the grain bed and it was like stirring cement.My efficiency dropped to 65% and came in under my expected gravities.(I sparge to a preboil volume for a 60 minute boil as my kettle is only 7 gallons and lose 1.5 gllons per hour)
I'm thinking a single batch sparge would have been better with the larger grain bill but can't prove it

Theoretically, no. You should get slightly lower efficiency with a single sparge, all other things being equal. Braukaiser.com has extensive literature on the subject.

With larger grain bills the efficiency goes down anyway as Ms Bastard shows. She may want to mash in a bit thicker, or just use more grain.

I go for anywhere between 1.25 and 1.5 quarts/pound and anywhere in between. I try to end up with 5 gallons of sparge water to get two sparges at 2.5 gallons each (give or take a little).

Double batch sparges have given me an average of 85% with a high (twice) of 91%. This is with a stainless braid on a round 10 gallon cooler.

I would naturally assume a double sparge would be more efficient, no? An opportunity to stir in the middle of things seems like it would mix up and channeling or "sweet spots" in the mash and get more out of the grain.