Optimizing armour for maximum ass kicking.

My friend Scott found an unusual picture of me in my Battle of the Nations rig from last year without my surcoat on.  You can see the back plate which I based on a 15th century find from Rhodes.  If you look carefully, it follows the curve of my spine like a back brace might, so any impact is distributed over the largest area possible.  This is a very good thing when you're getting hit very hard by blind side shots.  I can't find footage of it, but a Russian guy hit me so hard in the back that I flew what felt like 20 feet.  It didn't hurt or leave even the smallest dent.

I wanted to point out the contrast between the shape of my greaves (the calf armour) and the ones worn by my buddy Rich, sitting down just to my right.  His greaves are essentially cylindrical, while mine are tapered substantially toward the ankle, and curved to follow the muscles.  This does a few great things. 
1.  Like the back plate, it distributes the force over the whole area under the plate more evenly, so shots hurt less.
2. The curve gives the plates a lot more strength than a flat rectangle.  There may be some lengthwise curve to his splints, which does help, though a more complex curve is substantially more rigid.
3. It reduces the weight a lot. 

Splints are an excellent choice for protection per dollar since they're easier to make than a fitted greave, but they have to either be thick (heavy) or be spring steel. If they're simple rectangles, not tapered or shaped, the result is a cylinder.  So the surface area is 2pi X the radius X the height of your shin, right? (Think of it as cardboard tube, when you slice it lengthwise, it unrolls into a rectangle with a height of your shin, and a width that's the same as the circumference the tube had.) With me?  Ok, a cone of the same height that tapers to a point (which would be somewhere around the foot) has a surface area that's 2pi X the radius X the distance from the point of the cone to the rim of the cone.  That last one is the hypotenuse of the triangle that fits inside the cone.
Cylinder: 2 X pi X r X h
Cone:             pi X r X s
So s is going to be a bit more than h, but not a ton- probably around an inch for my leg.  And yes, your ankle isn't a tiny point, so the cone approximation isn't perfect, and we've ignored the gaps between the splints.  What this indicates though is that there's a substantial weight savings, about 25%, in the shape alone for a cased greave.

Because the greave is so much wider than a splint, and the force it takes to deform that complex self supporting curve is so great, you can make it out of thinner metal than the splinted greave.  And you're saving the weight of the leather and most of the rivets (there's still a hinge and straps in most cased greave designs).  And this weight is near an extremity.  Sprinters run in insanely light shoes to increase their foot speed.  I chose to do the same, and it paid off.  The victory isn't all about the armour, or all about me, this wouldn't have happened without the other tough buggers in my squad, but watch what happened in our final fight against Belarus.  I'm the guy with the full sleeves and the poleaxe on the right:
Our 5:5 fight vs. Belarus and another view.
Now Belarus is a top tier, very competitive team that's been doing this sport for years.  I managed to pull the attention of two guys, out sprint their flanker, and knock down two of their men in the first few seconds of the fight. We suddenly got a 5 on 3 match because of a quick read, and quick feet.  Our center leveled another of their guys in the chaos, but was quickly blind sided.  Even given ample time to think about it in a chess match that would have been a good tactical trade, since the result gave us a 4 on 2 fight that we soon won.