Strategy (2) doesn't tell you how to come up with the initial prices, and bookies can potentially lose a significant amount from giving "bad" initial prices. If an individual is winning a lot of money from a bookie repeatedly because of these bad initial prices, then it is a sign that they might have a better model than the bookie, and so it is in the bookie's interest to ban them, since sports betting is a zero-sum game: every dollar you win from a bookie is a dollar that the bookie loses.
I worked for a gambling syndicate. We often made money from bad initial prices. Many bookies tolerated us because they wanted to know what we thought was mispriced and rapidly adjusted their odds after we started betting.
It was a balancing act though. They really wanted to know what we were doing, but didn’t want to lose too much to us. So there was some give and take / bartering around the fair value of our information in the form of our accounts being banned and limited or bets being voided. But they definitely didn’t want to eradicate us.
> If an individual is winning a lot of money from a bookie repeatedly because of these bad initial prices, then it is a sign that they might have a better model than the bookie, and so it is in the bookie's interest to ban them
I don't think this follows. If an individual is winning a lot of money repeatedly in this way, it is a sign that the bookie should give their bets a lot of weight when adjusting prices. But that information is something the bookie might want.
If bookies want better prices they can pay for prices from places that have good models. Or they can buy / build their own models. What you're suggesting doesn't make sense from an economic perspective.
See https://news.ycombinator.com/item?id=45483917 , sidethread.
Thanks! I definitely have more to learn in this area.
The vast majority of small bookmakers in the UK don't come up with their own prices. They either copy other bookmakers or pay for them.
They also typically use off the shelf software for book management and risk.