Back to the Future II plot hole?

From the Back to the Future II IMdB FAQ (Back to the Future Part II (1989) - FAQ - IMDb):

Isn’t the sports almanac way too thin for fifty years of sports statistics?

Depends on how detailed and varied the statistics are. We only know that it has the scores of various games and the winners of some horse races. With small enough font, the almanac could accomplish this - or by using a cross table, which could fit a whole season of results on half a page.

Old Biff tells Young Biff, “All you have to do is bet on the winner, and you’ll never lose.” This line seems to indicate that only winners across different sports are recorded in the book. It’d be pretty thin then, even for 50 years of statistics of “football, baseball, horse races, boxing.”

What just got me thinking while reading the timeline posted by silenus upthread:

When Doc takes Marty and Jennifer to 2015 in the beginning of BTTF2, why do they still keep existing and form a family?

I never stopped to think about it, but this really doesn’t compute. Einstein, being the world’s first time traveller, essentially vanished for one minute. Why didn’t Marty, Jennifer and Doc vanish in a similar fashion for 30 years?

Does anyone have an explanation for that?

Because when they went thirty years into the future, there was a near-absolute certainty that Marty and Jennifer would choose to go back to their own time when they were done. On the other hand, there was a near-absolute certainty that when Einstein went one minute into the future, that Doc wasn’t going to send him one minute back in time for no reason other than to screw up his experiment and potentially telefrag his dog.

I’m just trying to wrap my head around the concept of going into the future.

Going into the past makes sense, just make sure you’re not running into yourself. But going into the future just seems to open a huge can of worms - I just don’t see how you could meet yourself, because you just skipped the years that it would take to grow old and raise a family. If it was almost certain that Marty and Jennifer would return, then why is Marty Jr. still a wuss, if wiser, traveled-back-in-time Marty Sr. could have raised him so much better (especially since the Rolls-Royce accident also seems almost certain not to happen, taking all of the movies’ events into account).

My head hurts.

It’s like a ball of wibbly wobbly timey wimey stuff.

The time changes hadn’t propagated to 2015 yet, so when the Marty and Jennifer of 1985 went to 2015, they were seeing the lives of Marty and Jennifer who hadn’t time travelled to 2015. If they’d stayed longer, maybe the whole McFly family would’ve faded out after a week the way Marty started doing in the Fish Under the Sea dance.

Is there a Marty and Jennifer who didn’t travel to 2015? See, five minutes after they left, they’re gone. Five years after they left (1990), they’re gone - how is babby formed?

The situation in 1955 is different, because it doesn’t involve doppelgängers.

Enchantment Under the Sea dance! :stuck_out_tongue:

“Telefrag”? I like it! “Time-frag”?

My issue is Biff: he’s not smart enough to figure out how to work the DeLorean on his own! Mr. Fusion, 88 mph, setting to board to when he wants to go: he doesn’t have any of that information! I really think he would have forgotten all about what he thought he saw anyway.