Vig Allocation

Does anyone have any knowledge of how books allocate the juice they charge on large moneylines? When calculating fair odds, it is not hard to find a significant "edge" at some books for some sports somewhat consistently. I suspect to protect themselves from big upsets the vig is split more equally within the line (linear), as opposed to proportionally as fair odds calculations apply it. Thus, the edge you think you are seeing doesn't really exist.

Example -- sharp book posts the following:
Underdog = +450
Favorite = -600
Fair Odds = +/-471
You find +500 and think you have a 5% edge. I am thinking more juice is applied to the dog and your fair odds calc is off. And maybe this allocation increases as the line increases, since the spread widens and books are protected on the favorite through increased total vig.

Anyone with any knowledge of how the books generally do this, or resources I might find useful? I can't seem to find much discussion on this. Apologies if this has been posted before -- I looked back a few years and didn't see anything.

Quote: kuma

Example -- sharp book posts the following:
Underdog = +450
Favorite = -600
Fair Odds = +/-471
You find +500 and think you have a 5% edge.

The +471 represents a no-vig line. It does not represent true odds. I would say a much better way to estimate both true odds and good bets would be to use the best widely available odds on the favorite and underdog. In this case it would be underdog +500, favorite -600. Instead of 5% player edge, I would consider it a 2.33% house edge

Quote: kuma

I am thinking more juice is applied to the dog and your fair odds calc is off. And maybe this allocation increases as the line increases, since the spread widens and books are protected on the favorite through increased total vig.

Depends on the book, the game, and the market. Some places will move the lines based on action more than others. Las Vegas books that are closely attached to the rest of the casino often add more juice to the favorite, because the big bosses have the slots/table games mentality and they end up in a position where they would rather give up some of their edge in exchange for more consistency each week. Online books, or Nevada books with more autonomy try to keep the house edge and vig consistent on each side.

471 is the no-vig line and it’s also the true odds of the game if you bet randomly. Various analyses show that you will lose exactly the juice over the long term no matter which side you bet on...meaning the no-vig line is true odds. The line is just a function of where the money was bet, but the bettors are very accurate. There are a few exceptions to this...taking home dogs in MLB and NFL can be slightly advantageous since slightly more people like betting favorites, which skews the line a little.

I don’t think you’re going to see a +500 line. If market is 471 and a competitor takes 2% instead of 4%, the line will be 460 (always under 471 since that’s the starting point and books discount payouts off of that). There can be arbitrage opportunities where a profitable line exists above 471, but they don’t last long and usually just tiny profit.

Quote: Ace2

I don’t think you’re going to see a +500 line.

I don’t think you’re looking very hard. Right now can find both +190 and -195 on tonight’s baseball game (I bet the favorite). The “sharp” Sportsbook (whichever one that happens to be) most likely has a no-vig line outside of those numbers. And this is a Sunday night during baseball season. Imagine a full football or basketball card. It would be almost impossible not to be able to find multiple bets that beat what you claim to be true odds at any given time.

Remember, no one has to bet randomly. If one place offers +450/-600 and another offers +500/-700, there may be four different prices available, but only two that we would ever consider

Isn't no-vig the same thing as true odds? Otherwise, how would you have a bet with no vig, which doesn't represent the true odds? That's assuming the same vig on both sides and the market being accurate.

Quote: RS

Isn't no-vig the same thing as true odds? Otherwise, how would you have a bet with no vig, which doesn't represent the true odds? That's assuming the same vig on both sides and the market being accurate.

I would say that would be true using a no-vig like with the best widely available numbers. The original question was about looking at a no-vig line from a so-called "sharp book." Whenever someone tries to use that to represent true odds, they generally get crushed.

I was thinking the no-vig line was the same as true odds, as long as the vig is distributed proportionally between the favorite and the dog. I do not think this is the case with larger underdogs on the moneyline, because you certainly can find better lines than, for example, the Pinnacle no-vig line, for some sports, multiple times each week -- you just have to search around quite a bit as TomG stated -- and they are typically on the underdog. In an efficient market you would not think this would be quite so common, so I am thinking some books might distribute the vig disproportionally, but I just don't know that for sure.

TomG gave me another perspective in taking the best lines on both sides from the universe of books you are looking at and calculate the no-vig line based on that; maybe not just the line at Pinnacle or whatever specific book you are looking at.