Stitch strength heresy - Lock vs Saddle

[AlZilla]

So, I'm going to commit heresy. I've had time to ponder this while spending about 8 hours hand stitching a project.  Here I go ...

I don't believe that the saddle stitch is any "stronger" than the lock stitch. We often see it said, but I just don't see any reason for it.

Hear me out - any given stitch length is the same whether it's locked by machine, or a hand sewn saddle stitch. If the thread is the same, the strength is equal. Each stitch line has the same number of stitches and, thus the same length of thread.  The bottom thread on a saddle stitch goes all the way to the other side. The bottom thread on the lock stitch goes half way, thens around and goes half way back. So, everything is equal.

I can see the argument that if I break one side of a saddle stirch, I still have the 2nd thread running end to end. That's not "strength", it's durability.

I'm willing to be wrong.

[fredk]

Its a matter of semantics

[DJole]

In the lock stitch, the threads are pulling on each other. In the saddle stitch, they are only pulling on the leather. 
I wonder if that might make a difference? Of course, it's only speculation without somebody putting the threads to a test on an industrial testing machine.