Confused about efficiency calculations on beersmith.

Any help appreciated (is Brad around?)
I have been using beersmith for months and love it but am having trouble with efficiency calcs.  I first set up my equip profile and have been using 73.8 for my efficiency ( after taking the avg of about 4 all grain batches ). 
This Sunday I brewed a batch using 14lb 2-row pale and 8oz victory for the grain bill.  I did a 6 gal batch shooting for about 8 gal preboil (actually 7.91gal) and got exactly 8gal after 1/2nd runnings (batch sparge, 3.75/4.25gal).  I use 1.25gal/hr boil off and recommended cooling loss.  The recipe preboil OG was supposed to be about 1.055 and postboil OG was 1.065 using my profile. 
I got a preboil OG of 1.050, and a postboil OG of 1.059.  Ok, so I figure that my efficiency for this brew is low, but when I calculated the efficiency ( using http://www.brewersfriend.com/brewhouse-efficiency/ , and another online calculator), it comes out 74.77 which is higher than mine?  This same thing happened on my last brew too.  I can't figure out where the discrepancy is unless it is the 0.09gal dilution because I got 8gal instead of 7.91?

Brew House efficiency covers efficiency from the mash to the fermenter. This also include what happens in the fermenter. Since the calculators you references state, "for approximation use"  you don't need a 73.02184596 % efficiency, 73 is adequate. The numbers you missed were because of your mash. You can use a refractometer to measure the sugar in mash prior to sparging. It is not the OG, it is your pre boil gravity, PBG before you boil. The original gravity is the OG which is what you measure after the boil. The FG, final gravity is what you have after fermentation. We have no way of knowing what #'s you are plugging in where. Really, just keep an eye on your mash efficiency and mash process. When I started using Beersmith2, I was confused over this too, so I trusted Brad's genius qualities and adjusted the brew house efficiency to take into consideration the mash efficiency and PBG, I was getting consistently with the same base malt, and magically it became 75 %. Set it and forget it! Can you taste the difference between a 67% and an 80% brew house efficiency brewed beer? When I came to the trial version of Beersmith2, I was thrilled by the water calculator. I was using several other brewing software programs to calculate everything I could to make a better beer and come up with an ideal water since I build from reverse osmosis water. My trial time was about 10 minutes, before I purchased Beersmith2. You will make great beer in time! Great numbers don't make great beer. Experienced brewers make great beer!