[Unknown User]

I'm new to sportsbetting and trying to develop my methods. I want to measure whether my bets are winning but don't want to rely on measuring ROI as it will take a long time to achieve sufficient sample size. I've learned about the method of comparing odds taken to closing lines. I use oddsportal.com average closing line because that's convenient with the bookkeeping.

I have a few specific questions about this method:

1. What would be a good sample size using the "beating closing line method" to assess whether I am betting in a profitable way?

2. By what approximate margin should I beat the oddsportal closing line average to be able to bet break even over the long term?
(I realize the oddsportal closing line average is not as strong as hard to beat as the best available closing line)

I posted the same questions in the newbie forum but although it got 600+ views there were no replies, so I figured I should try in in the think tank.

[Maargs]

Gonna get back to you with detailed response later on

[SportsMushroom]

do not use oddsportal average odds, it is not accurate at all because its an average of lines from mostly recreational books with stale lines and 40 cent vig


best use pinnacle closing odds, they are the most efficient in shaping their lines due to the massive amounts of money they take on each event and the fact that most professional gamblers play there, so their closing lines are as efficient as possible

considering that pinnacle has a 1.5-2% theoretical hold, I am assuming that if you can beat their closing line by 2% you should at least break even in the long run

I dont know what a decent sample size is, but it probably should be in the thousands

[gui_m_p]

I'm new to sportsbetting and trying to develop my methods. I want to measure whether my bets are winning but don't want to rely on measuring ROI as it will take a long time to achieve sufficient sample size. I've learned about the method of comparing odds taken to closing lines. I use oddsportal.com.prx.proxywebsite.co.uk.pr x.proxywebsite.co.uk average closing line because that's convenient with the bookkeeping.

I have a few specific questions about this method:

1. What would be a good sample size using the "beating closing line method" to assess whether I am betting in a profitable way?

2. By what approximate margin should I beat the oddsportal closing line average to be able to bet break even over the long term?
(I realize the oddsportal closing line average is not as strong as hard to beat as the best available closing line)

I posted the same questions in the newbie forum but although it got 600+ views there were no replies, so I figured I should try in in the think tank.

I agree with mushroom, do not use the average because you will be using books with high juice (and consequently low odds), and this will delude you, beacuse you gonna think that is always beating the closing.

Pinnacle is fine for it. For american sports you can also use 5dimes or bookmaker. For soccer SBObet is good too. One tip: rank the books by " juice margin" on oddsportal (it's there a column with that). Those with lowest margin are the most efficient, and the ones you should use.

The difference of profit you are taking should be higher than juice. Example: if you bet at 2.00 and it closed 1.95, you took a extra 0,05 of profit. 0,05/0,95 = 5,26%. If the juice is lower than this you made a good bet and is likely a long term winner if you hold that CLV.

Other method is to set a non-juice line (read here to know how http://sportsbettingsites.org/bettin...ig-calculator/) and compare the line you took with it. If the odds of your bet is grater than the non-vig line, your bet is very good.

I just disagree with mushroom about sample size. The skill of a handicapper is not suscetible to variance like a game outcome. Thus with one hundred plays you'll have a good background.

[Unknown User]

Thankyou for the great answers.

The no vig calculator is awesome.

Short recap to make sure I understand you guys advice:

I look up Pinnacle closing odds, put them in the novig calculator ----> compare to the odds my method is betting-------> few hundred - few thousand bets later, If I'm beating that line, I have a great idea whether I'm a winner.

[gui_m_p]

Short recap to make sure I understand you guys advice:

I look up Pinnacle closing odds, put them in the novig calculator ----> compare to the odds my method is betting-------> few hundred - few thousand bets later, If I'm beating that line, I have a great idea whether I'm a winner.

Exactly.

[Unknown User]

Cool. One more thing:

If I gather closing lines and convert them to no-vig lines, does it really matter what book I collected them from? The result should be kind of similar right? Unless the particular book is schewing the line really hard in a systematic way but I guess there are enough sharps to keep them all pretty much in line.

I mean: I could basically use the closing line of interwetten and convert it to no-vig and it would be as strong as the pinnacle one converted to no-vig. (I'm using the Pinnacle one but wondering about this because its not easily accessible for some sports)

[SportsMushroom]

Cool. One more thing:

If I gather closing lines and convert them to no-vig lines, does it really matter what book I collected them from? The result should be kind of similar right? Unless the particular book is schewing the line really hard in a systematic way but I guess there are enough sharps to keep them all pretty much in line.

I mean: I could basically use the closing line of interwetten and convert it to no-vig and it would be as strong as the pinnacle one converted to no-vig. (I'm using the Pinnacle one but wondering about this because its not easily accessible for some sports)

well, if you have pinnacle lines, why would you bother using interwetten lines


the thing is, when you are calculating the no vig line, you are intuitively assuming that the vig is spread evenly between all sides, but that may not be the case, so there is a margin of error involved, and the fact that pinnacles line is as close to the no vig line as it comes, means you are decreasing your margin of error

now obviously for games were pinnacle does not provide a line you can use a line from another book, but you can be sure that it will not be efficient, obviously there would be almost zero liquidity on that game, probably no or little line movement, so beating the closing line would probably be impossible.

of coarse in such games is where you can cripple a book. because of low liquidity and inefficient lines, if you are sharp enough to calculate your edge, which would be quite significant, you can make a lot of money

[Unknown User]

All the bookkeeping takes a lot of time and sometimes I'm taking an U 5.5 or something and Pinnacle has the U 5 but not the U 5.5, the U 5.5 will still move because all the UX markets are correlated and I could probably convert a U5 to a U5.5 but I'm trying to be a little bit efficient with the bookkeeping. (hmm maybe I should figure this out)

The point you make that some illiquid and exploitable lines will be very hard to beat against their closing line but all the easier to beat in terms of real profits is interesting. I did figure some of these illiquid bets don't work the same way and I keep them in a seperate spreadsheet. Unfortunately they are not as common as the 1% edge bets.

That the vig is not spread evenly is definitely a problem. I think it will be challenging to figure that out. But I think I need to because profit margins are so small as is. I guess it's really oversimplifying things if I'd assume the vig on dogs/draws is less and I should be more inclined to bet those for 1% margins?

[SportsMushroom]

you probably are right, juice may be concentrated on the favorite and the over, since those are the bets that the public bets on