>>1073179There's some mechanical advantages to some types of blades when it comes to physical strength, but mostly it comes down to the use of the blade shape.
With the #1 you get an easy to make, relatively strong knife with a large cutting surface, you'll see it on a lot of the cheaper chef's knives and utility knives, there's nothing wrong with that but it lacks one thing when it comes to say #4, 5 & 6 and that is- tip control.
When you have the axis of your handle, line it up and on something like #4 and #6 you have the point either dead centre of that axis or slightly higher/lower and that lets you use the tip with a bit more precision because you are essentially following that axis of the tools handle from the palm of your hand and you can see where the cutting tip is going quite easily. This is important when you're skinning things, doing fine slicing and in the case of #6 probably stabbing something.
That's what those shapes lend themselves to doing well, at the cost of having a little less cutting surface than say the extremes like #2 (Cimeter or Breaker) which has a large cutting surface and #3 (Spanish) which is designed to have a lot of cutting surface, good tip control and somewhat less mechanical strength.
#7 & 8 are pry-bars or chopping blades where its all about strength
#9 & 10 are in that brokenback, sheepsfoot style as they prevent the tip from digging too deep or the tip isn't relative to the blades intended function, you see them on a lot of pen knives and are fairly popular for crude surgical procedures like cutting the balls off sheep and cattle as it won't inadvertently stab the shit out of them
