[Cosimo]

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I was reading somewhere that if you make a pass bet, and get double true odds on it along with 2 other come bets and true odds on those the house edge drops to something like .60% ..

Does it drop further with more come bets?

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Come bets don't change the edge on anything. Every bet has its own edge. You could, if you want, play some blackjack, some poker, some craps, and then spin the roulette wheel a couple times, and then say "I played against a 5% house edge," but that doesn't change the 1.4% edge that the house has on your pass bets. Making a 1.4% bet and then a 9% bet changes the average house edge on all the money that you wagered, but ... um ... so what?

The phrase "get double true odds" doesn't mean anything to me.

In craps, you can make what's called an "odds bet" on a pass line bet. An odds bet is a side bet that pays at true odds. All casinos limit the odds; usually on the Strip it's 3x 4x 5x, and at other casinos it might be limited to double odds, 10x on any point, or 100x on any point. The 10x and 100x limits are there to draw locals, "look! 10x odds!" The 3x 4x 5x odds just make payoff faster, meaning a faster take. Any decent book on craps will explain all this; I'm just trying to communicate the terminology that I'm familiar with.

A pass bet has a house edge of 7/495 (approx 1.4%). A pass line bet with single odds drops the house edge to .85%, and it continues to drop as the allowed odds increases. That is, the edge on the total amount that you wagered is falling -- but notice that the amount that you are wagering is increasing. Your pass line bet was still made with a 1.4% house edge, while the second bet has a 0% edge.

Place a $5 pass bet, and then put a billion dollars behind as your odds bet. Since the billion dollars is at 0%, the house edge on your total amount wagered is very close to 0%. We might even call it a 0% edge since it's so close. No-one will notice.

But your expectation hasn't changed! In fact, when you established a point, your expectation FELL. When you make a $5 pass bet, you expect to lose 7 cents -- but there are two components to that pass bet. The first component is the come-out roll. (There are 8 ways to win immediately on the come-out, and only 4 ways to immediately lose. This is where most of the winnings in a line bet comes from.)

The second component is establishing a point. If you establish a point, then you are (on average) a 22% dog. Twenty-two effin percent. That's huge. You're always more likely to seven-out than to hit your point, no matter what the point is. For points of 6 and 8, the house edge is 8%; for points of 5 and 9, the edge is 20%; for points of 4 and 10, the edge is 33%. Kiss your money goodbye. You really don't want to make points.

Well, now that your original bet is looking pretty grim, hey! look! You can make a 0%-edge bet! All you have to do is increase your variance!

Placing an odds bet doesn't increase your EV; it just increases the amount that you bet without changing EV, ie effectively lowering the house edge. But, again, focusing on the house edge is smoke and mirrors to distract you from the fact that your EV hasn't changed. If you want to make an odds bet, then realize that the ONLY thing you are doing is increasing your variance. You'll win more when you win, and lose more when you lose.