Doesn't Bif succeed at the whole sports betting scheme. That's why he's rich and powerful when Marty goes back to the future. No?
Yes, but he doesn't go back in time with future money. He goes back to give the book to his younger self. His younger self then waits till his 21st birthday and bets on races I believe. The point is, it isn't that farfetched an idea to do what Biff did. What this infographic doesn't get at is the very real possibility that Biff's actions could actually changes future sports results and render the almanac useless.
How can someone betting change the result of a sporting matching, well except where those sports matches are corrupt?
Butterfly effect my friend. Biff bets on some sporting events and makes a bunch of money. His making money and spending it and having higher stature in the World can then cause unintended things to happen, which might include the outcomes of certain matches or even whether those matches take place.
Yes the butterfly effect could change a few results, but his almanac covered way more than a few results. It takes a massive belief in the butterfly effect to believe that all result would change. Then again if a few changed and it changed his behaviour (which it would as he would start losing, or not winning as big), it would tend to return to the original timeline. As the trilogy has shown is inclined to happen in the BttF world, matter of fact the film tends to ignore or refute the butterfly effect. For example when Marty knocks down the tree in the first film, the sole world change is the mall goes from the Twin Pines mall to the Lone Pine mall. If it was following the butterfly effect more closely the mall would have changed layout or not been there.
So given the world in the BttF universe, the butterfly effect, provably, is negligible to non-existent.