How to scale 10 gallon batch to 5 gallon and keep same mash efficiency?

I am scaling a recipe from 10 gallon to 5 gallon and my mash efficiency goes up.  Is this normal in that mash efficiency increases when scaling down?  I want to hit the same exact numbers from my typical 10 gallon batch.  I can post more information but am not sure what information would best help figuring this out.

*bump*

Are you saying beersmith changes the efficiency when you scale or that you system is more efficient when you brew 5 gallon batches rather than 10?

Assuming the latter, it is common for systems to be "tuned" to a batch size.  The geometry of your mash vessel can have an affect as does your sparge method.  Using a false bottom versus a manifold has an affect.  Sparging 10 gallons in the same time you sparge 5 could also affect your efficiency. 

So, you don't what to change your efficiency unless you you are stabilizing it.  You simply need to know what it is at each batch size and adjust the recipe accordingly.  Consistency is paramount.

it actually is the former.  i have the exact same equipment but two different equipment profiles (see attached screenshots of two different profiles).  one for 11 gallon batches and another for 6 gallon batches.  when i go to scale from the 11 gallon to the 6 gallon the mash efficiency changes and i can't figure out how to prevent that.

Note the "brewhouse efficiency" field in the profile.

It looks like you pasted screenshots of the same profile both times:  10 gallon stainless kegs.

I'm not seeing how it would be possible for your efficiency to stay the same or why you'd want the mash efficiency number to be the same even if you've already brewed like this and figured it up on paper.

It doesn't matter if BeerSmith's mash efficiency matches what you get on paper, what matters is that BeerSmith predicts your gravity using the correct batch size.
When I am backtracking over old recipes after entering the actual measurements I adjust the brewhouse efficiency until BeerSmith agrees on the predicted and actual gravity.

But if you absolutely insist that your mash efficiency matches either what you get on paper or what you get using one way or the other in spite of having BeerSmith correctly predict your gravities, once you have your correct losses entered adjust your brewhouse efficiency, the only place it can adjust is the mash efficiency.

Using the same equipment, it seems to me that your efficiency would have no choice but to be better with a larger batch.  Your dead spaces would be a constant, but account for a lower percentage of the overall batch. 

I.E., losing a quart of a 10 gallon batch is "less" than losing a quart from a 5 gallon batch.

I think I understand now after seeing your replies.  My brewhouse efficiency needs to be calculated for each batch size and that will probably make my mash efficiency closer to each other (if not the same).  Thanks.