Has to be the biggest one mentioned so far.
Stuff like Orr/Lemieux/Crosby being healthier doesn't really change history, per se. Maybe more career stats and an extra championship for the respective franchise, but it's not like they retired at age 22 or something and we never knew what they could have done.
Gordie Howe on the Rangers legitimately alters the course of NHL history. Detroit is still a great team in the 1950's, but are they great enough to win multiple Cups? Does Montreal fill that vacuum and go Boston Celtics 8 or 9 in a row? Or is a Rangers team with Howe able to win Cups in the 50's? Do the Rangers become a complete disaster throughout the 60's? Probably not, but now there's a chance the Red Wings do. Could that post-expansion Rangers team with Ratelle and Park emerging have won a Cup with an old, but still elite Gordie Howe in the fold? Does hockey become a major sport in the US decades earlier if the game's greatest star was on Broadway?
actually, Orr basically did...
Orr's final full season of hockey was age 26...for comparison, Karlsson is 27. After that he only plays in 36 games over the next 3 seasons combined.
By age 26 he already had:
8x Norris
3x Hart
2x Cup
2x Smythe
2x Ross
8x AS-1
Calder
915 pts in 657 games (1.39 ppg)
If they had simple arthroscopic knee surgery back then, Orr misses 6 months and is healthy after. If Orr gets to play until 35, that means he retires in 1985. So he gets to play in the high flying 80s AND play with Ray Bourque
Also, dont forget that Orr played his entire career with damaged knees. The injuries started his sophomore year (1968)...Orr played more than 75 games in a season only 4x
It is not unreasonable to think that the Orr/Gretzky debate is considered truly neck and neck if Orr has a full career. Youre looking at:
- at least 1,500 points
- 3-6 Harts
- 12-15 Norris
- 2-5 Ross
- 2-4 Cups (Boston for sure beats Montreal in 78 and 79 with him)
- 2-4 Smythe
- 12-15 AS-1