The explanation of Kahle hooks is pretty complex and often controversial.
First
Kahle is a trademark name from Wright-McGill (Eagle Claw)
and several manufacturers have similar designs with other names.
Originally designed in the 1950s for use by ocean longliners the hooks
were called "English" hooks. Eagle Claw marketed Kahle hooks as a
preferred option for bulky baits. The wide gap allows us to use a smaller
wire size and lighter weight hook on large baits. This becomes an advantage
by allowing live baits to be livelier and live longer because they are stressed less.
Smaller wire size also requires less pressure for penetration. This is critical
for those with baits at long distance or when fish swim toward you or sideways
creating slack in line.
I always sharpen hooks before fishing till the point will dig into a thumbnail.
This is not an option available with "super" hooks with hardened steel and I
am unsure if I can even sharpen a circle hooks point.
Kahle hooks come in offset eye and offset point styles. Hooks with offset eye
will rotate (cam) the hook point into fish much the same as circle hooks.
Snelled offset hooks must have mainline outside the bend to cam. Offset
points are either right or left of parallel to hook shank. They increase hookup
ratio with an increase in gut hooking fish.
I do not believe flathead bite or suck baits off of a hook. I feel they completely
engulf a live bait and then clamp down to prevent fish from escaping. Their stomach
collapses around the fish to quickly suffocate it. With this secure hold the hook
tears out of the bait (as I wish) and the hook slips to a tooth pad or the hook eye exits
the mouth and cams.
In the event that you gut hook a flathead, I suggest you reach in and gently back
the hook out. If your fish is too small to get your hand into the stomach you may
want to cut the hook off. The hooks will rust out very quickly. There is no advantage
to use stainless steel hooks unless you fish in the Ocean so mentioning that SS
takes longer to rust out is pointless.
Colateral damage is inevitable with any hook design but circle hooks have
an edge (by design) to decrease that damage.
Circle hooks have points parallel to the hook shank. The point cannot dig in
until the eye exits the fishes mouth and turns the point into the fish (normally
the soft tissue between tooth pads). These hook excel in current when teamed
with rods that load up (bend a bit) and rod holders. The hooks slide out as fish
increase pressure (move) until the eye exits the mouth and the hook sets itself.
A normal hookset with a rod often jerks the hook free before it has time to cam the
point into the fish.
I would like to point out that I do not recommend any tackle as best for everyone.
I do suggest that each man recognizes what he wants his tackle to do and then
find the items that best suit those needs. What I use is best for me (in waters I fish)
but I always rig for conditions/baits when fishing other waters. I normally follow local
fishermens advice (unless it proves unsuccessful

.
Discussing the merits of hook design is very complex. Every manufacturer claims theirs
is best without explaining why. Fishermen are confused with these claims and when their
experiences differ with other fishermen. Fishing is a learning experience and unfortunately
most lessons are from our failures.
I just hope I can help someone catch more and bigger cats and reduce the pain normally
felt from failures of losing a fish or becoming frustrated with fruitless trips.
Catchabiggun,
Robby