...Still though, I've seen him double dip a couple times and win massively...
The problem for him is that over the long run his massive wins won't outweigh his smaller but more numerous losses.
...but you're hoping for a wedge in between two spreads and your odds are pretty terrible.
The best way to explain hedging to people (and many other things in life) sometimes instead of doing the math is just to say, "If it were profitable, everyone would be doing it."
If Bridgewater, or JP Morgan, or Google, or whoever, with their 12-figure resources, computing power, and MIT-level smart people haven't figured out a way to make money from arbitrage under the current framework and regulations of sports betting, there is no chance in a million hells that someone like me has thought of an idea that will work.
Betting exists because of irrationality of humans and the thrill they get out of it. If humans were rational, betting would not exist. There is literally zero possibility of anyone
reliably coming out ahead in the long term. There are sharps who make money, but it is at a level of reliability (and likely rate of return) orders of magnitude less than something that already exists (diversified investment in the stock market). In other words, you can reliably say that you will make money long term by investing it diversely in the stock market (even with very little knowledge due to mutual fund risk reduction). It's been proven for years and years and years.
Gambling, on the other hand, has never been shown to be a reliable money-maker (even to those who have tons of knowledge), because there exists a third party (the house) that is after profit,
and sets the rules. As soon as someone smart finds a loophole and exploits it (card counting, playing games with MLB spreads, etc.), the
house is free to change the rules at will, and they do.
That $50 I mentioned putting on Illinois will reliably make me more money in my 401k, but that's not as much fun
. There's no rational reason to gamble when other avenues exist to make more money, other than the thrill.