I am Mike and I really appreciate everyone chiming in on this thread, especially Sal!
The opening I used was a SpyderDrop; however, it was not from the usual right-side, clip-carry position. It was a draw from the right back pocket.
My first tactical folder was a Gerber Folding Sportsman II with a "Flicket" attachment for one-handed opening. That's what I carried in high school in the late 70's, before Sal changed the world by single-handedly inventing the modern folding knife--introducing the pocket clip, purpose-designed, ambidextrous one-handed opening, and serrations on a folder. Because folders didn't have clips before Sal, I carried in my back pocket, pivot pin to the right. My draw was to reach in, palm facing my butt, curl my fingers under the knife, lift up, and do a thumb opening.
I switched to a Delica in my back pocket in 1998, when the 98 model was released. After a bit of experimenting, I chose to position it with the pivot pin facing to the left. My draw is to reach in the same way, but pinch grip the Hole. I then draw, SpyderDrop, and go to work. This method of carry is great for anal-retentive corporate environments where having a knife clipped to your pocket gets people bunged up.
Inertially opening a well-made knife takes considerable skill--just as it should be. Properly manufactured knives use "self-closure" mechanisms to exert force on the blade to draw it closed during the last portion of the arc of its movement and to keep it that way when the knife is in the pocket. Overcoming that force requires an understanding of proper technique and considerable practice. Knives that don't provide that force and are too easily opened can be dangerous if carried improperly.
Inertially opening a knife does accelerate wear on the mechanism. How much wear depends, again, upon the technique and finesse of the user, the type of locking mechanism, and the engineering and manufacturing quality of the knife. I have seen very expensive, but poorly engineered, knives have their lock mechanisms compromised after just a few hard inertial openings. On the contrary, one of my original Endura trainers is still going strong after almost 10 years of constant use and literally thousands of inertial openings.
Whether the wear of inertial openings is greater or less than the wear caused by SpyderDrop openings also depends upon the technique of the user and the weight of the handle. As we say in MBC, "If you try hard enough, you can 'F' up anything." I usually allow the handle to strike the meaty part of my palm near the pinky side to "buffer" the impact on the lock. This method also allows you to open the knife silently, by opening it most of the way until it hits your palm, gripping the handle with the pinky and ring finger, and then opening the blade the rest of the way as you ease the lock into position.
Your opening method will depend upon your carry method and the amount of training you invest in developing your skill set.
Thanks again for a great discussion.
P.S. Thanks for your patience with my slow response. The weather here was great this weekend, so I spent more time on my bicycle than behind a keyboard...
Spyderco Special Projects Coordinator
Founder and Lead Instructor, Martial Blade Concepts