Gretzky/Mario didn't exactly change the game because nobody could emulate them.
Orr didn't change the game because defensemen couldn't do what he did.
If that's the criteria for revolutionary, none of those guys were revolutionary.
Revolutionizing:
1. Things are done within a system for an amount of time.
2. An individual or group challenges how things are done by doing them differently.
3. What they do differently is successful.
4. The things they do differently can be imitated by others,
5. The amount of people who imitate said individual or group grows to the point where it's normal.
vs.
Enhancing:
1. Things are done within a system for an amount of time.
2. An individual or group takes what is being done and excels at it beyond what others are capable.
3. Others keep playing the same way as the system hasn't been challenged, but rather we have been shown the upper echelon of what the system is capable of.
4. People strive to reach that level.
Bobby Orr changed the game because nobody even thought about playing the position the way he did. He changed how people viewed the position and how it was taught. - "
In contrast to the style of hanging-back defensive play common in the later 1950s and 1960s, Orr was known for his fluid skating and end-to-end rushing. Orr's rushing enabled him to be where the puck was, allowing him not only to score effectively but also to defend when necessary."
The Russian Five revolutionized the game because they redefined how hockey was taught in North America, and also changed how North Americans viewed European players. - "
the five also changed how hockey was taught in North America, in no small part because of the value they placed on puck possession. In the words of Jim Lites, "Everybody used to dump the puck in and chase it down behind the net. The Russians changed that. They changed our game.""
Wayne Gretzky revolutionized the game because he really changed how people viewed the utilization of the team around him. - "
"He was, I think, the first Canadian forward to play a true team game", said hockey writer and former NHL goaltender Ken Dryden. The focus of the game before Gretzky's arrival, he said, especially among the Canadian teams, was on the player with the puck—getting the puck to a star player who would make the big play."
What exactly is McDavid revolutionizing? What is he changing about the current game? It was already trending towards speed and skill before he came along. He's simply the best at it.