It's that time of year when many of us are out buying new skates to fit those feet that keep getting bigger every year.
One thing to consider is the "radius" of the skate blade. This can have a significant effect on how much speed a player can achieve from the skates.
First some background. The "radius" is defined as the curvature of the skate blade when viewed from the side. This is not to be confused with the depth of the groove that is created by sharpening the blade - i.e., the small curve that can be see when looking at the blade from the front of the skate.
A skate blade's radius is measured by the radius of the circle that the entire length of the blade would touch if it were resting on the bottom edge of the circle. (Picture the skate balanced on the bottom inside edge of a hula hoop.) Typical skate blade radii range from 7 feet to 14 feet. (Note that a typical sharpening groove is on the order of 1/2".)
A 7-foot circle has the smallest radius which results in a very rounded skate blade which would rock quite a bit if moved back and forth from toe to heel. The shorter radii are theoretically intended for centers and possibly wingers who value the ability to turn quickly moreso than the ability to get significant pushing action from the skate blade.
Conversely, a 14-foot circle has the largest radius which results in a much flatter skate blade. A blade shaped like this would not rock much if moved back and forth from toe to heel. The longer radii are theoretically intended for defensemen who value the ability to get significant pushing action from the skate blade (i.e. speed) moreso than the ability to turn on a dime.
In my opinion, all skaters should skate with the longest radius offered in order to get as much pushing action from the skate blade as possible. In order to master proper power skating technique (which allows a skater to maximize his or her skating potential), the skater must be able to execute the final "toe flick" which involves digging into the ice with the toe of the blade at full leg extension. A flatter blade shape brings the toe of the blade closer to the ice at full extension which makes it easier to master the "toe flick".
I recently learned from the sharpeners at Zwicker's that skate blade radii vary quite a bit with new skates as shipped from the manufacturer. Therefore, it is important to assume nothing about the radius of your new skates. Ask the seller to shape your new blades to a 14-foot radius before they sharpen them. If they do not understand what you are talking about, then take your new skates to someone who does.