I totally disagree with your post.
In the computer age professional gamblers can easily disguise massive bets by breaking them into thousands of little pieces.
It was much harder and riskier in the pre-computer days.
I totally disagree with your post.
They’re plenty of websites that track movements money on all legal gambling sites simultaneously, so it’s almost impossible to conceal mass movements of money at legal gambling sites.
Compared to when gambling was done thru illegal methods, when someone with information could spread bets around and no one would know because the fact they were taking bets was illegal.
For example, when the NBA referee Tim Donaghy was caught gambling on games it was harder to uncover because he was gambling with illegal sites.
Besides, legal sites handle many millions more than illegal sites today which makes it even harder to move the line versus before when multiple small sites that are illegal could move their lines on smaller bets.
Sports books will respond to unbalanced betting by adjusting point spreads to bring betting back into balance. Even if a large amount of money is bet on one side in the form of many small bets, the books will adjust the spread and it would be obvious. Bookmakers set spreads based on getting equal amounts bet on each team and they generally are very good at it. Very rarely do spreads move more than a point or two in either direction, and larger moves often are explained by news that comes out after the original spread has been set (most often an announcement that a starting QB is injured and will not play). Large changes in the spread for no apparent reason would not go unnoticed.