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I-Skid-My-Pants
25 Mar 11 13:25
Joined:
Date Joined: 19 Mar 11
| Topic/replies: 16 | Blogger: I-Skid-My-Pants's blog
Hi can any one tell me how to calculate the correct odds for over/under 2.5 goals, if the goal expectancy is 2.9 goals in the game
Thanks
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Report kenilworth • March 25, 2011 1:35 PM GMT
A rough guide would have 2.7 goals expectancy at about 1/1 (2.0).For each
0.1 on the expect, the price would go up or down by about 10%, in your
case (2.9) would have 'unders' at 2.21 'overs' 1.82.GTBOH.
Report the silverback • March 25, 2011 2:18 PM GMT
Poisson is a good enough friend. Although not all games with the same goal expectancy should have the overs / unders priced the same.
Report kenilworth • March 25, 2011 2:39 PM GMT
Why not ?
Report the silverback • March 25, 2011 5:58 PM GMT
I suppose a simple way of putting it is that there are distributions within distributions dependent on other   factors, one of which is probably obvious.
Report Coachbuster • March 25, 2011 9:02 PM GMT
a second goal is more likely once a goal is scored ,and a third is more likely again  etc etc
Report kenilworth • March 25, 2011 9:58 PM GMT
silverback, your post is very vague, and says nothing that is evident (to me)
coachbuster, there is no evidence of a goal being more likely after a goal.
Report the silverback • March 25, 2011 10:24 PM GMT
A 2.7 game with a one goal favourite won't necessarily have the same distribution of goals as, say, a 2.7 goal game no favourite. (It possible for the 2.7 to be the correct expectancy for both).

(Difficult to explain things when you're dealing in expectancies)
Report kenilworth • March 25, 2011 11:48 PM GMT
A 2.7 expectancy with a one goal favourite will have a distribution
of
Report kenilworth • March 25, 2011 11:59 PM GMT
A 2.7 expectancy with a one goal favourite will have a distribution
of 1.85 fav - 0.85 outsider, no reason why that shouldn't be, and IMO
won't be any different from equal favourites with the same goal
expectancy. Where's the evidence that contradicts ? If the sides were
of equal ability, then the expectancy may be lower, but 2.7 is 2.7
what ever way you look at it. The fav is more likely, the outsider is
less likely but whichever way 1.35 + 1.35 is the same as 1.85 + 0.85
in my book. (Sorry about the previous post but I accidently hit the
submit button !)
Report Trevh • March 26, 2011 3:02 AM GMT
There is no evidence of a goal being more likely after a goal

There is evidence Kenilworth, although it's not quite as simple as just saying a goal is more likely after a goal. I have records for over 30000 matches that show the reformed odds after a goal are often  wrong (too generous) depending on the goal minute. When analysed as a whole at a certain point of all matches, they show that matches with a goal should be backed for another goal, and those that are goalless backed to remain goalless.
Report kenilworth • March 26, 2011 6:27 AM GMT
As 92% of matches produce a goal it would therefore be the simple thing
to buy goals if what you say is correct, or even just to wait for a goal
then buy. The spread firms are quite good at what they do, and as soon as
a goal is scored, they adjust the total goals by simply adding one. I hear
what you say but my experience is different. A simple test would be to see
the average goals per match from half time, when there is either no goals
or one goal already scored.
Report Trevh • March 26, 2011 9:56 PM GMT
You would also need to know the half time odds for each match, as matches that kicked off at the same odds will show different odds at half time depending on goals, i.e. a goalless 10.0 kick off will likely be 3.5, and a 1-0 likely 3.7 at half time, so the market does recognise that. Where the market is wrong is at a different point of the matches, not half time.
Report kenilworth • March 27, 2011 12:14 AM GMT
I suggested half time as it is a fixed point in every match. Half time odds
are usually automatically related to the betting on match odds, goal expectancy,
etc., so if the betting is 6/4, 11/5, 5/2, goals expected, say 2.6 then press a
button and you have the half time odds. I'm sure you will say ''not always'' and
you will have the advantage without pointing out examples. To end, I would say
show me a Spin middle price of perhaps 2.7 goals, and I will show you around
2.0 unders or overs, perhaps you will disagree, but show me examples where I am
wrong.
Report Trevh • March 27, 2011 2:40 AM BST
I'm not saying you're wrong, I'm saying that at specific points of matches as a whole generalisation over thousands of examples, backing another goal after a goal pays a profit long term. Backing a goal at the same point in goalless matches shows a loss long term. I don't do anything other than c/s markets, so have no comments on match odds or overs and unders, but thinking about it again, profit does also depend on the kick off 0-0 odds, certain odds ranges don't show a profit.
Report kenilworth • March 27, 2011 9:39 AM BST
Backing a goal at the same point in goalless matches shows a loss long term.

Are you saying that the price of a goal being scored at 0-0 is inherently incorrect,
that it would therefore pay to back 0-0, or are you talking about a specific point
after the kick off ?
Report Trevh • March 27, 2011 3:30 PM BST
Laying 0-0's in good liquidity matches can be profitable because punters hold the price up for too long, hence at a certain point the price is too big and becomes a back.
Report kenilworth • March 27, 2011 3:58 PM BST
That is interesting although i have never been keen
on laying around those double digit prices.
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