From the games I've watched...
Of the five major sports (incl. soccer), hockey is the sport that had its players evolve the most through training/technology.
Football is a debatable 1a/1b with hockey.
If I was to ballpark, I'd say:
Soccer players in the 70s are 95% of soccer players today. 2010 Soccer Team 1, 1970s Soccer Team 1... 2010 Soccer Team win an extra time.
Baseball players in the 70s are 90% of baseball players today. 2010 Baseball Team 6, 1970s Baseball Team 5.
Basketball players in the 70s are 80-90% of basketball players today. 2010 Basketball Team 92, 1970 Basketball Team 80.
Football players in the 70s are 70-75% of football players today. 2010 Football Team 28, 1970 Football Team 20. *Football is mostly about SIZE these days. The SIZE of modern football players would be way too much for 1970s players.
Hockey players in the 70s are 70-75% of hockey players today. 2010 Hockey Team 5, 1970 Hockey Team 3.
And equipment/tools help, but I'm still imagining giving both eras of players same equipment. (I mean, hockey players smoked in between periods in the 70s. Smoked!)
There were some very good athletes in 1970s hockey... and I believe some (if not the average) of those hockey players were as smart or smarter, as players today.
But todays' players skill of skating, especially, and coaching is FAR FAR superior to 1970s.
On a surface as big as hockey: 200'x85', having more speed and more strategy is going to create dominance.
To be honest, I think most upper NCAA college teams could compete with the Habs of the 1970s... that's how good I think the hockey skill level is these days.
[Now - the old timers won't want to admit this. I'm 40+, I don't want to say it. But its true. The game is just blazing fast now and the players are trained to do all the right things with the puck. Dump when its right, hold the puck in the corners when its right, pinch at the right time. Players in the 70s were smart about analyzing what to do with the puck when they had it (single-step-forward thinking), but they didn't have the same puck training AWAY from the puck - that kids do now (a second-step-forward-thinking of ingrained training thought process)]
Well... its not really fair to cross-compare eras.
Anybody should really only (ever) be compared relative to their peers.
20 years from now, the current group of players will be far inferior.
The world is ever evolving.
But yeah, in summary, hockey has grown in leaps over the last 40 years, moreso that any of the other major sports, IMO.