When the NHL outlawed Overdrive, they labeled it a 'performance enhancement' and said it gave an unfair advantage to the goalies who were using it over those who were not. The IIHF and other pro leagues accepted this reasoning and followed suit. Since that time, there has been no change in Overdrive's legal status in any pro league.
However, if you are playing minor hockey in Canada, the CHA, which governs all of minor hockey in Canada, expressly allows it. Their memo still stands, and if you want a copy of it for referees or officials, click here to print it up.

I don't expect Overdrive's legal status to change anytime soon, but it will eventually be legalized, and not just because it prevents a lot of injuries, but also because outlawing Overdrive goes against the very nature of sport. I'll explain.

The NHL outlawed Overdrive because it worked, it increased mobility, but sport is all about increased mobility, as per the Olympic motto - Faster, Higher, Stronger. When roller skates (below left) became roller blades and offered the better mobility of in-line wheels, roller hockey became a sport and roller-blading became a popular activity. When people discover better ways of moving, it's likely to turn into a sport.

Above right is a very old skate, and let's see how many sports were created as they evolved. Of course there's hockey, and figure skating, ice dance, speed skating, and short track speed skating. The same applies to bikes. As the original penny-farthing evolved (below left), so did sport.

Look at any sport, and you'll see that as soon as people find a new way to move, they start having fun with it. Increased mobility becomes sport.
In order for mobility to become a sport, it has to be INCREASED mobility, pushing towards the limits of human potential. The problem is that this kind of mobility requires increased grip at the contact points, otherwise things become risky, even dangerous. Imagine speed skating or figure skating or skiing with dull edges, or mountain climbing without enhanced grip.

Sport is entirely dependent upon grip. Without it, you have no Faster, Higher, Stronger, and for most sports, the primary contact points needing enhanced grip are the hands and feet.

 

Baseball batters use batting gloves, and pine tar. Pitchers use rosin bags.(right)

Racquet sports (left) have all kinds of grips, which are then coated with adhesives.

 

The same goes for golf clubs, and then the players wear gloves, and then the gloves are treated in various ways (right).

Weightlifters use chalk and weight bars are knurled. Football players use Stick'em. All sports use grip enhancement for the hands.

In fact, look at my toothbrush and razor below. Where your hands meet a product, you'll likely find grip enhancement.
Grip enhancement for the feet has become just as precise, with sport-specific and surface-specific shoes being refined every year. Above left are old baseball cleats, while in the middle is a newer model from Easton, and to the right is the latest from Mizuno, which went all-out with the cleats.
Tree climbing evolved from an off-hours competition for loggers into a sport, helped along by improved spikes. Similarly, ice climbing spikes have added to the safety and popularity of this growing activity. Meanwhile, snowshoes (below left) have seen increased mobility and grip enough to make it competitive.
In 1925 Adi Dassler and his brother (the founders of Adidas) were making soccer shoes with nailed studs and track shoes with hand-forged spikes. Their shoes gained worldwide attention at the 1928 Olympics in Amsterdam, and by the time of Adi's death in 1959, he held over 700 patents related to sports shoes and other athletic equipment. It's hard to imagine what sports would be like if his spiked shoes had been outlawed. Above right is Adidas' latest soccer shoe (at the time I wrote this), the Predator. Among many new features, it has replaceable magnesium studs and a grooved forefoot (green tab) for better grip on the ball and 20% more rotation. Some players wear them while others choose not to.
Skates began as flat plates of metal attached to shoes, and to move, you needed a type of ski pole. In the 1500's, a Dutchman invented the skate blade. Grip was improved, out went the ski poles, in came sharpening, and eventually various sports were born. Blades have evolved with each sport according to how the athletes need to move, allowing for different sharpenings, shapes, and rockers.
Figure skates
A thicker blade, curved at the front, straighter and longer at the back for stability. Picks at the toe enable a wide variety of dance moves, spins, and jumps.
Speed skates
A very long, thin blade, with no rocker. Designed for long, powerful strides going forward only, with the skater moving right foot over left.
Hockey skates
A thinner blade with a rocker front and back for movement forward and backwards, for hard stopping, and for turning in all directions. 		Goalie skates
A flatter, thicker blade for stability, to withstand impact, and to help with lateral sliding. Goalie movement includes a lot of lateral sliding against the grain of the blade. Only goalies use the skate blade in this way.

And the innovation continues...
Speed skate blades: The long track Klap blade is hinged at the toe for a longer push and smoother stride. The short track skate (middle) has an adjustable offset blade to allow for sharper turns in one direction (far right, top view).
Figure Skates now offer Parabolic blades (thin in the middle, thick at the ends) Side-Honed blades (thick at the stanchions and edges, thinner in between) and Tapered blades (thick at the toe, thinner at the tail). They also offer improved picks, including a cross-cut version.

These blade alterations improve the athlete’s mobility while also increasing the appeal of the sport. Imagine figure skating without toe picks, without the incredible leaps that depend upon this minor 'performance enhancement'. And it will be hard to go higher than a 'quad' without improved toe picks or some other enhancement.

Goalie skate mobility was not a big problem with the old stand-up style, but it became one as shot speed increased. Goalies adopted the wider butterfly style to stop the faster shots, but this stance leaned the boot closer to the ice (left) and made boot-outs more likely on many moves. As well as reducing mobility, these slips also increased the strain on the core and led to chronic injuries that hadn't hampered goalies before. A new way of moving created mobility and injury problems.

Skate companies have recently introduced no-cowling skates that reduce the width of the boot and increase the height of the blade (arrows left), thus lowering the angle of boot-out, but the reduction is not enough and boot-outs persist, along with the chronic core injuries that plague goalies at all levels.

Overdrive is simply another in a long line of grip enhancements for the hands and feet, a special type of equipment that is crucial to athletic performance.

  • Some grip enhancements improve mobility so much that sports are created, like the invention of the skate blade.
  • Other grip enhancements improve mobility to a lesser extent, yet they alter a sport forever, like the toe pick or the cleat.
  • Other grip improvements may not seem as necessary to the observer but offer important benefits to the athlete. Overdrive falls into this category.

The NHL has managed without Overdrive, but the removal of many other grip enhancements would go equally unnoticed. Would baseball batting gloves or rosin bags be missed? Do golfers need cleats? Skiers once skied without steel edges. And why should the luge allow spiked gloves?

Do cyclists need clips (right)? They didn't have them before. How about runner's starting blocks (far right)? As minor as some grip enhancements seem to be, the athletes using them insist they are a necessity. And they're right.

Athletes move at speeds that push the limits of human mobility, and with speed, comes danger. A cyclist racing down a hill must have his foot secured, because a slip could result in serious injury. Similarly for skiers needing sharp steel edges.

Golfers would likely develop all kinds of lower body injuries if they had to tee off without cleats. It wouldn't just be counter-productive motion cutting into their performance, it would be counter-muscular motion jerking them in the opposite direction. That is how you injure yourself, when fully tensed muscles are pulled even more, like a taught rope being pulled and frayed. Look at the sprinters or baseball pitcher to the right and imagine a fully-tensed pushing leg slipping back off the starting blocks or rubber. That is what happens to goaltenders when they play without Overdrive - they boot-out and their groins fray.

These seemingly minor grip enhancements play a crucial role by allowing athletes to safely push the boundaries of mobility, thereby pushing the limits of their sport. Higher, Faster, Stronger happens with these small changes, and that's why they are allowed. Following this principle has never failed sport and it would not have failed the NHL had they allowed Overdrive. There might have been fewer goals, (until forwards figured out better ways to score - they always do), but fans would have been treated to seeing the best goalies in the fastest game in the world moving even faster, and with far fewer career-ending injuries.