Attack them early and hard before they get their bearing. Also, if you have a decent BR and have been in the business a while, read their house rules several times very carefully. Some of them have made mistakes that have been exploited for lots of $$.
One simple example: one book offered the bettor an option to 'self exclude' from gambling which essentially closes down their account. Turns out they messed up how this worked and if you did this with pending bets, they were all cancelled. So bet 20k on big favorites every day until one seems to finally be losing and then self-exclude. Some might call this a scam but there you have it.
Another more complicated example is how they handle props. Someone made a lot of money betting Aaron Judge under 1 HR props on days where Aaron Judge was unlikely or officially OUT of the lineup. Now most places would cancel player props if the player didnt START the game. But one place said they only need the player to enter the game for the bet to have action. So, Under 1 HR at like -400 is a fantastic bet because if Judge doesn't start then he will only come to pinch hit once (or better, pinch run or defensive sub). The fair price on Judge not hitting a HR in games where he doesn't start is probably closer to -2500.
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