Tuna bend hooks are a small trick that really can improve your catch ratio!These pictures illustrate a test that I conducted matching tuna bend hooks against parallel shanked hooks. This will give you an example of how you can (and should) conduct a similar test of your own to determine which style hooks you should be using yourself . This test was very enlightening!
I started with a Mustad 7732 parallel shank hook (like the one in the left on this picture) and a 7691S tuna bend (right). Both hooks were the same size with the only difference being the tuna bend. Notice how the tuna bends hook point slightly aims back at the shank. Next I crimped identical lengths of leader to both hooks with a loop at the far end that I could insert a dowel for pulling on them both equally. I started each hook into a piece of cardboard to simulate a hook catching into hard tissue in a fish's jaw area. This picture shows the two hooks before I started pulling on the dowel.
The last picture shows the result. The parallel shank hook "cocked" back instead of pulling straight into the cardboard. Note that the straight shank hook did finally pull into the cardboard but it took a tremendous amount of pressure to do it. Worse, it pulled into at at such an odd angle it appeared that it could come back out very easily through the excessively large hole that it made.
The tuna bend went straight into and through the cardboard with minimal pressure while the other hook was still cocked back. The hole that the tuna bend hook made was small as a result.
The picture below illustrates the cocked attitude of the straight shank hook. In the meantime with minimal pressures the point on the tuna bend hook behind it is already halfway through the cardboard.
This test was an eye opener for me. I changed to tuna bend hooks immediately afterwards and my hook-up ratio improved dramatically as a result. You have to try a similar test on your own to fully understand.