Brians

The simple answer to this question is no and yes. No, any goalie
can use Overdrive but yes, butterfly goalies get more out of it.
Anyone can use Overdrive simply because it corrects a problem inherent in goalie skate design and made worse by the way goalies move. If you're wearing goalie skates and you move like a goalie, you need it. Here's why.

The protective shell makes goalie skates (right) about 15% wider than regular skates (left) and goalie skates also sit 20% lower to the ice.
skates at an angle
When the skates roll to their sides, the boot of a goalie skate hits the ice at 45° while the regular skate hits at 30°- a 33% difference.
Actually, it's really the toe area (A) where the width is an issue. The heel is much narrower and can grip to a much lower angle.
rolling skate
You'll lose your edge if you roll the foot below 45° because the boot will lever your blade off the ice. If there's weight on the foot, it will propel a slip. A lot of weight means a big slip, not much weight means a smaller one.

If goalies played hockey like forwards, there wouldn't be much of a slipping out problem. Anyone who has ever played out in his goalie skates knows that the side of the boot hitting the ice is no big deal and instead, you'd be more likely to complain about the rocker of goalie blades.

However, once you go back in the nets, your movement changes completely and slipping out can become a problem, or a serious problem, depending on how you play.

Goalie movement is mostly lateral, or side to side movement, something forwards almost never do. From the stance, the legs will separate into a push or a kick or a slide.

A goalies' feet spread out on a regular basis and again, this is something that forwards almost never do. The key to slipping out is how far the feet separate because this is what rolls the boot into the ice. As soon as one or both feet separate enough to roll below 45°, you've got a slip.
The problem is not confined to goalies who play the wider, butterfly style. The prerequisite is width and there are lots of non-butterfly goalies who use their flexibility to play wide.

However, it really doesn't take that much foot separation at all to hit the 45° point. On almost any push or kick, a goalie could easily hit that point with no trouble at all because the legs can supply power to a much lower angle. Watch a tennis match or a baseball pitcher to see the full extension they get to unload their power or maximize their reach. In essence, there is a 45° speed limit on goalies and this is like putting a 45mph limit on a Porsche. So why don't we see goalies slipping all the time? Because most of the time, they obey the speed limit. Since they don't want to slip, they'll limit their power or reach.

Without Overdrive, all goalies of all styles are limited in this way. All goalies will also have slipping problems but this will be most acutely felt by goalies who play the butterfly, or have very good flexibility.

You'll notice that all the goalies in the NHL using the blade belonged to at least one of these two categories. I expect the need for Overdrive to only increase in the future because the butterfly and the more recent ProFly style are quickly becoming the standard and extreme flexibility will soon become prerequisite.

Also:
Since width and height are the factors determining the angle of slip-out, anything that increases width or decreases the height will worsen the situation. On the 'About he Boot' page I look at things that can widen the boot. A worn down blade will reduce the height.Actually, this is how I came up with the idea for Overdrive. If the main blade gets low you'll slip a lot. It was happening to me and the addition of Overdrive was originally meant to extend the life of my skates, which I really liked, by getting rid of the slipping.

While a standup (or hybrid) goalie can benefit from the blade, a butterfly goalie can get more out of it because Overdrive reduces several negative aspects of the style. I'll look at 4 problems with the butterfly:

moving out of the stance-----staying on your feet-----5 hole-----recoveries

The butterfly stance can be difficult to move out of for two reasons.

1) A wider stance rolls the boot closer to slipping out.
Compare A vs. B (above). When a butterfly goalie moves out of the stance, the foot rolls into the ice sooner. He'll have to either stop the move or roll into the side of the boot and slip out. Both options limit mobility.
2) A wider stance by nature doesn't have as much push in it.
Lateral push comes from separating the legs sideways and maximum push comes when the feet start together. The drawing shows two different stances: feet far apart (top) and feet close together (bottom). The big black arrow is maximum stretch for a move right to left. If the feet are together (bottom) then the total push is red arrow 2. With the feet farther apart (top), then total push is red arrow 1.
It's like the difference between a short and a long step. You can't take a powerful step when you're already stretching out. In the drawings, the difference is the total push (red arrows), which powers the move.

Other Implications

Limited mobility out of the stance contributes to another problem for butterfly goalies: playing too deep in the net. It's not easy for anyone to get out there and challenge because it's not just a question of extra movement in and out but it also requires more lateral movement.
Every goalie knows that at position A you have a lot less ice to cover to get to the middle of the net than at position B. As we've seen, it's just harder for butterfly goalies to make that move so it's difficult for them to challenge at the top of the crease. There isn't a lot of confidence when they do move out and instead of focussing only on the puck, there's a 'back of the mind' worry about going for a swim or getting back to the net. They have to pick their moments to attack but there's always a tendency to drift back to the safety of the net. This is death for a butterfly goalie because the style is all about going down at the right time. If you're in too deep, timing won't help you as the good shooters will destroy you up top. When shooters do get you farther out, they'll sense that it's time to go around you and you'll have to scramble.

With Overdrive, even at the widest stance you'll still have plenty of edge to get a strong push. Hopefully you'll become less hesitant to attack and when you do, it'll be easier to track laterally or retreat quickly to the net.

With the wider stance and the deeper bend of the knees, a goalie in the butterfly stance is always close to going down. The leg muscles work hard and there's a lot of outward pressure on the feet to give the stance a natural pull towards the ice. When you combine this natural pull with the previous section on movement out of the stance you can see why most moves a butterfly goalie makes send him down to the ice. This contributes to the #1 problem butterfly goalies have --going down too early. While it's an easy problem to identify, it's very hard to correct. In the heat of a game with shooters doing everything they can to get you to move first and go down, even if your timing is right on, you can still get caught.

In the strip (full clip is on 'Strain on Slips') Potvin doesn't intend to go down but just tenses with the fake. With the wide stance, sometimes that's all it takes to roll the skates onto the boot and cause a slip.

Overdrive allows you to control the precarious nature of the butterfly stance to stay on your feet longer. It gives the stance the security it needs so you can hold your position solidly in the heat of a game. You'll still tense and flinch when shooters throw their bag of tricks at you but it won't be so costly.

The 5-hole is bigger on a butterfly goalie and it's not just because of the wider stance. If we look at the drawing again, it shows how the wider stance rolls the feet closer to slipping out.

Goalies can get around this and put the skates at the higher(standup) angle by separating the knees.
*Note in the Turek shot that if you're wearing 40" pads it's going to be hard to tighten the 5-hole down.
Separating the knees gives you a bigger 5-hole but it also raises the angle of the skate to give you a little bit more roll for pushing off.
Overdrive removes these disadvantages. You can take a wide stance with the knees together for a smaller 5 hole and retain all of your mobility.

Implications of a smaller 5-hole.

The advantage to the butterfly style is that it covers the low corners. With a standup style, on a shot to a low corner, the goalie has to make a kick save. The problem with kick saves is that they're slow because you're moving a lot of weight. As you move up to better shooters, it's hard enough seeing the puck let alone moving the feet with pads and skates to stop it. The feet almost have to be there already if they're going to stop a hard, low corner shot. That's where the butterfly style comes in. The wide foot position covers these corners or leaves just enough to deter shooters from going there. The tradeoff is that you leave a larger 5-hole but it's worth it because closing down the 5-hole is easier than kicking out. You have gravity working with you and only one move option (5-hole) instead of two (left or right kick). The thing about Overdrive though, is that you can lower your stance so that the 5-hole is also small enough to deter shooters. If you can get it below a certain size, you can be sure that a shooter will hesitate or look elsewhere. This can make a huge difference in your game, primarily because it will reduce the need to go down, but also because it can reduce your worrying about the 5-hole. Mentally, the 5-hole always looms large so if you can gain enough confidence to feel that it isn't a desirable target, it can clear up a lot of mental traffic and allow you to focus better. When you do need to close down the 5-hole, a wider stance will shut it down faster because of all that outward pressure on the feet (red arrows, above). You have a shorter distance to drop and you go down quicker.

It's not just that butterfly goalies go down more, it's also the way they go down. The feet have to 'wing out' for as much width as possible. While the coverage is great, the problem is that the feet are in a slightly awkward position and are a longer way from getting up. To get your edge you have to reposition the foot by bringing it back into the body so that it can angle up. Since the legs spread out farther, they have farther to go for a recovery.
With Overdrive, the edge to move with is right there. With practice, you'll just have to angle the foot up a bit to secure the foot for a recovery or move while down. You'll save the time needed to bring the leg back to the body. In both strips, my feet are spread out but the right leg ,does just a quick twitch to get me up.