Opening lines accuracy

[the shadow]

I was wondering if a line opens at -150 and closed at -130, what would happen if that same game opened at -170,
would it still close at -130 ?
In other words how dependant is the closing line on the opening line?
If that -170 doesn't close at -130 then the closing line isn't gospel as many of us believe.
Food for thought!!!

[CHUBNUT]

Too much emphasis is placed on opening and closing lines, the line is what it is. A -150 line is not going to open -170 so its a completely different situation, where the line moves to depends on many things which nobody knows.

[sharpcat]

I was wondering if a line opens at -150 and closed at -130, what would happen if that same game opened at -170,
would it still close at -130 ?
In other words how dependant is the closing line on the opening line?
If that -170 doesn't close at -130 then the closing line isn't gospel as many of us believe.
Food for thought!!!

Theoretically speaking the answer is yes the number should always close on its true market value and the opening number would have no effect on that. considering that a moneyline is just an expression of the probability of a team winning the line should almost always close withinin the accurate range of each teams implied win percentage.

[the shadow]

Would the books only move the-170 line so much because of middling and other propositions.
Therefore the opening line sets the stage for the closing line.
Sharpie, I agree it should close at market value but the opening line is very relevant to the closing line .
In short if the opening line is off 20 cents,is it possible the closing line is off the same.
So whatever you open a line at ,it will always close at the same number. I doubt this very much.

[sharpcat]

Would the books only move the-170 line so much because of middling and other propositions.
Therefore the opening line sets the stage for the closing line.
Sharpie, I agree it should close at market value but the opening line is very relevant to the closing line .
In short if the opening line is off 20 cents,is it possible the closing line is off the same.
So whatever you open a line at ,it will always close at the same number. I doubt this very much.

I think if the books opening line was off that drastically (assuming the scalpers were scalping within the same book) would rather have a player scalp his bet for a 5% profit than they would like to see a player remain in a position where he would have an EV of 10%. Scalpers sacrifice roughly half the value of their bet when scalping out of a profitable position.

This is why the books that all other books mimic their lines from release overnight lines with low limits. The overnight lines with their low limits allow the books to adjust their lines at minimum risk so that by the time they are taking high limit wagers the lines have already been fine tuned.

Much like the stock market if a stock that should be worth $4.00 a share is currently $3.00 a share the market will continue to buy up the stock until it reaches its true market value, the same principal applies in all markets.

If a book does not move its line to the most accurate implied win % they are putting themselves in a -EV situation and will likely get pounded by sharp players, a book should worry more about players taking strong positions on them than they should worry about scalpers taking them for crumbs.

[the shadow]

Sharpie ,thanks for the input.Maybe you could direct to a thread in this forum about how closing lines fare against opening lines.
i've seen the damn thread but can't find it. Supposedly the closer was slightly better than openers.(but not my much)

[Justin7]

Too much emphasis is placed on opening and closing lines, the line is what it is. A -150 line is not going to open -170 so its a completely different situation, where the line moves to depends on many things which nobody knows.

Epic fail.

There are two reasons an opener moves. 1. It was wrong. 2. New information came out, changing the fair line.

If you're not thinking about things like this, you're just gambling.

[suicidekings]

Epic fail.

How many times a day do you roll your eyes and sigh after reading a post, Justin? I'm guessing at least 5 a day on average.

[IrishTim]

How many times a day do you roll your eyes and sigh after reading a post, Justin? I'm guessing at least 5 a day on average.

On the contrary, I'd imagine.

[Data]

On the contrary, I'd imagine.

With all the nonsense he posts I would not.

[Justin7]

With all the nonsense he posts I would not.

Data,

Don't get me wrong. I enjoy ST: TNG. It's good background noise. But I have a serious question for you.

Do you even bet on sports?

If your answer is yes... go back to the original question I addressed. Answer it yourself. And explain how I responded with nonsense.

I'll admit to some rather random posts, but not in the Think Tank, which I had hoped would focus on serious discussions.

[Data]

go back to the original question I addressed. Answer it yourself. And explain how I responded with nonsense.

Justin7, I was referring to your overall performance, not to this particular post which actually made sense. However, the post I am replying to shows your abysmal level of reading comprehension which, in turn, strengthens my original point.

[Justin7]

Justin7, I was referring to your overall performance, not to this particular post which actually made sense. However, the post I am replying to shows your abysmal level of reading comprehension which, in turn, strengthen my original point.

You're going to talk trash, and accuse me of non-sense, except that you agree with me in the thread you brought it up? Please...

I actually took you seriously. Then I saw you congratulating BigdaddyQH and Curious for their grand contributions. I take it you agree with all of BigdaddyQH's "contributions" in the Think Tank?

[CHUBNUT]

Epic fail.

There are two reasons an opener moves. 1. It was wrong. 2. New information came out, changing the fair line.

If you're not thinking about things like this, you're just gambling.

your obviously slow on the uptake so I'll explain a little easier. There is no point asking if a -150 opener would move the same if it opened -170 because it didnt open at -170, A game that opens -170 has completely different stats to base that price on. As for your 1,2 nonsense on opening moves you once again post as if people are complete idiots.
Your points 1 & 2 are the same in principle as a genuine opening line is never wrong, IT IS WHAT IT IS. What changes that opening line is peoples opinions as new info is well covered by the books (you can only steal from slow books for so long)

So in the end it comes down to whether your opinion is better than the books over time. How this can be acheived is a more important debating topic than smart mathematical concepts on line movement which make the posters sound superior but sadly leads new bettors down the wrong path.

[Justin7]

Chubnut,

You said: "where the line moves to depends on many things which nobody knows. ".

Do you really stand by this statement?

You also said: "your obviously slow on the uptake so I'll explain a little easier. There is no point asking if a -150 opener would move the same if it opened -170 because it didnt open at -170, A game that opens -170 has completely different stats to base that price on."

You have never seen a game where two books open the same game (or market) 20 cents apart from each other?

Points 1 aand 2 aren't saying that openers are never wrong. They are suggesting that closers are (generally) never wrong.

[durito]

You're going to talk trash, and accuse me of non-sense, except that you agree with me in the thread you brought it up? Please...

I actually took you seriously. Then I saw you congratulating BigdaddyQH and Curious for their grand contributions. I take it you agree with all of BigdaddyQH's "contributions" in the Think Tank?

Yes that's exactly what he is saying.

[CHUBNUT]

Justin,
I dont want to get into a long pointless argument on who knows what and where that info takes them in regard of line movement. Nobody on any forum has ever posted how a bettor taking the best opening price on his selection compared to the closing line has fared over time but I would bet he hasnt lost much compared to the obsessive line movement brigade.
My main point is these forums have got to a point where all you read about is cheap quick mythical ways of beating the books instead of fostering posts about the fundamentals like being well versed in a sport

[Data]

You're going to talk trash, and accuse me of non-sense, except that you agree with me in the thread you brought it up? Please...

Where did I say I agreed with you? It just happened what your post could have been viewed as if it made sense. However, with your lousy wording it can be read both ways.

There are two reasons an opener moves.

The better way of saying this would be "There are two main reasons an opener moves." However, what are you saying in this thread sounds more like "There are only two reasons an opener moves." and that is something I would not agree with.

More on lousy wording, what is this

(generally) never

supposed to mean?

You argument in this thread reminds me of some of the "one trick pony" posters who learned that the closers are sharper than openers and keep bashing other posters who are yet to do so. The irony is that you all manage to make a bunch of nonsensical conclusions out of otherwise valid concept.

Chubnut,

You said: "where the line moves to depends on many things which nobody knows. ".

Do you really stand by this statement?

Well, I will play along. I stand by this statement in the "nobody knows" part. The market will move in the direction driven by the market agents who act upon their perception of the line value. When it comes to the "smart money", the unknown variables are both, the participants and their perceptions. However, there is no magical force that makes it one way street, there is a great deal of randomness here.

Here is really important point what I want to get across because I grew tired hearing otherwise. While the closers are sharper in general, any given closer could end up further away from the true line than an opener and that happens fairly often. Just not as often as when the closers end up closer (pardon the pun) to the true lines.

I actually took you seriously. Then I saw you congratulating BigdaddyQH and Curious for their grand contributions. I take it you agree with all of BigdaddyQH's "contributions" in the Think Tank?

It appears that we have different views on the concept of subforums. When I post here in the Think Tank and refer to your overall performance as a poster I refer to your posts in the Think Tank. When I post something in another subforum commenting on other people's posts I refer to their posts in that subforum where I post my comments. I do this on assumption that different people read different subforums. Your assumptions, however, do not seem logical to me. To answer your question, I am unaware of BigdaddyQH's "contributions" in the Think Tank and cannot comment on this. I do not read every thread and must have missed it.

[uva3021]

If you say the market will re-adjust itself to the implied probability, is this not a paradox? Assuming the implied probability is the market, lest you arrogantly believe yourself having a more sophisticated measure of evaluating teams, then the real implied probability would be either the opener or the market price after new information is presented? The rest, line movement that appears independent from information, would be simply noise and natural market fluctuation.

Though what is information in this sense. Information is a subjective quality because different people have access to the information that might be imminently effecting the line movement, so new information to one person may correspond to a line movement where another person with access to different information would perceive the same line movement as noise.

[Venkman]

always too much bickering in the think tank

[suicidekings]

If you say the market will re-adjust itself to the implied probability, is this not a paradox? (1) Assuming the implied probability is the market, lest you arrogantly believe yourself having a more sophisticated measure of evaluating teams, then the real implied probability would be either the opener or the market price after new information is presented? The rest, line movement that appears independent from information, would be simply noise and natural market fluctuation.

Though what is information in this sense. Information is a subjective quality because different people have access to the information that might be imminently effecting the line movement, so new information to one person may correspond to a line movement where another person with access to different information would perceive the same line movement as noise.

Wow... Is this post intended to just confuse the issue more?

(1) There's no paradox here. There's the true odds of an event happening (defined by numerous factors) that handicappers are attempting to calculate, and then there's the implied probability of an event happening (defined by the market activity on the ML). They're not the same thing. The market price is set to balance betting so it may not always accurately reflect the true odds of the matchup. However, in general, you could say that a line is much more likely to move in the direction of it's true value over time, with the understanding that it will not necessarily close at the optimal value (or always move in the expected direction) due to external influencing factors that do not directly affect the match (like public opinion).

[Spurspremacy]

Closing lines are usually more accurate than opening lines. So u would rather want to use closing lines than opening lines as a guide.

[u21c3f6]

One of the points that I have tried to make (I think unsuccessfully) is that there is no one probability or % that one can put on a sporting event. We are not throwing dice or spinning a roulette wheel or drawing a card. I tried to discuss this in this thread http://forum.sbrforum.com/players-ta...erm-value.html (a long thread).

While I would agree that the data set of all closers are more accurate than the data set of all openers, this says absolutely nothing (or at the least very little) about a single event. The opener may be more accurate or the closer may be more accurate, you have no way of knowing.

Take a person that can hit 53% on a subset of games @ -110 (no vig line 100). He is profitable. Now if he was to offer you the opposite side of his subset of games at +105, you would think that your wagers were +EV based on the no-vig line and you would be wrong.

Joe.

[Poogs]

It depends largely on market liquidity. If a game opens at -170 and the true line is -130, it has more of a chance of moving to -130 is the market is liquid. Meaning high limits and lots of wagering. The more efficient the marketplace is, the more movement you'll generally see.

As to the original question, its interesting. I would say that the line would move to its true line no matter what the opener was, but its possible that a line opened at -170 would close a little higher than one that opened at -150. But probably not.

[the shadow]

Thanks for all the replys.
If a book knows it screwed up on it's opening line because it's getting one sided,will they continue to move the line toward fair market value or will they move the line perhaps only 3/4 of the way therefore avoiding other issues (middling,etc)? Therefore the closing line would be dependant on the opening line.
I know lot of you guys have worked at books and how do they handle bad openers?
Is it possible they will only move it so much?
thanx!!!

[Pokerjoe]

Okay, because I think the OP was serious, I'll give the correct answer:
It's a behavioral economics thing.
The opening line is the anchor. So, yes, it has influence.

Put it this way:
If we ask one bunch of posters here what the line should be on a game BEFORE they see any lines ...
Then we ask a second bunch of posters (all chosen at random) what the line should be on a game AFTER they see the opener...
The second group's average answer will be closer to the opener than the first group's.

[Pokerjoe]

One of the points that I have tried to make (I think unsuccessfully) is that there is no one probability or % that one can put on a sporting event. We are not throwing dice or spinning a roulette wheel or drawing a card. I tried to discuss this in this thread http://forum.sbrforum.com/players-ta...erm-value.html (a long thread).

While I would agree that the data set of all closers are more accurate than the data set of all openers, this says absolutely nothing (or at the least very little) about a single event. The opener may be more accurate or the closer may be more accurate, you have no way of knowing.

Take a person that can hit 53% on a subset of games @ -110 (no vig line 100). He is profitable. Now if he was to offer you the opposite side of his subset of games at +105, you would think that your wagers were +EV based on the no-vig line and you would be wrong.

Joe.

This is true but how is it useful?

The point being made by the "beat the closing line" (BTCL) guys (at least, those who understand the idea) is really that BTCL is a better long-term predictor of sportsbetting success than actual bet results, at least until those actual bet results get to be a very large sample themselves.

So, to them, if you went 45-55 while BTCL by 5 cents, you did a better job of handicapping than someone who went 55-45 while losing to the CL by 5 cents.

I'm not a fan of BTCL, btw. Just like I'm not a fan of Kelly, and for the same reason: it's like looking for lost car keys under a street lamp, not because that's where you lost them, but because that's where the light's better. Math being the light here.

[u21c3f6]

This is true but how is it useful?

I think it is useful because I am trying to point out a possible fallacy that people have about sportsbetting odds. Unfortunately this really is a very large discussion that I find hard enough to do in person let alone trying to do this by typing on a message board but I will try to make my point.

In many posts, it appears that people are trying to use the odds as if these are absolute probabilities and they are not. They believe that whether or not your wager is + or - EV is totally dependent upon how your wager compares to the closing line and that is just not correct. Yes, closers will tend to be 50-50, but that is for all closers. If you truly randomly (throw a dart) select a sub-set of closers, that sub-set should also be close to 50-50. The problem comes in when your sub-set is not selected truly at random. That sub-set may or may not have the properties of the entire data set. The only way that one can "know" if a wager is + or - EV is to compare the results of a large enough sample of wagers selected by the same criteria. As I have tried to point out in other threads, there is no one side of any line that is inherently + or - EV. EV for sportsbetting is a comparison of your sub-set of wagers, it is not inherent in a single wager. I hope that made sense and/or is at least helpful to someone.

There is so much more that can be written but I will stop here.

Joe.

[djiddish98]

This discussion gets way out of my depth of knowledge, but I'd like to chime in anyway.

The true probability of a sports betting event is unknown. However, assuming an efficient market, I think we can say that the closing line is the best estimate of the true probability.

Therefore, I think you can determine the approximate EV of a single bet based on how the price you paid compares to the closing no-vig price. Using this language, I would also say that individual bets in a +EV subset can be estimated to be -EV based on the closing price.

However, the bolded assumption is (probably) a big one. This is also why I've become jaded by my (basic) econ education, because it assumes rational self interest, which is an assumption that falls apart fairly easily under duress.

[djiddish98]

Also, I'll add that if you had a valid and proven sample that could beat the closing line 55% of the time, I would either question

A) The validity of the sample
B) The efficiency of the market

[Krtica]

The root of all openings is ASIAN MARKET opening.
All , all , all odds , are readjusted when the asian market opens.
Those who do not understand asian handicaps and their markets , can not understand how the OTHER NON-ASIAN bookies adjust odds.
We can not judge anything from fixed bookies offers... Just from asian handicap offers... And exactly asian bookie movements (becouse thats the place where money flows)...

>>> lets see the limits for tonights game in wc2010 >>>

[djiddish98]

Pinnacle offers (I believe) roughly the same limits on World Cup action.

[the shadow]

Maybe all sports betting shoud turn to pari-mutual betting. We'll close this whole place down!!!!!

[mathdotcom]

Boys boys we are all on the same side here

[CFA]

Yes, the opening line will influence the closing line, but the influence is minimal.
The closing line will be different on games where the markets implied win probability is the same when the opening line (with vig) is within the boundaries of the market finding +EV vs. not finding EV.

Justin7 and all failed to address the crux of the OP's question.