blonde poker forum
Welcome, Guest. Please login or register.
March 28, 2024, 08:00:31 PM

Login with username, password and session length
Search:     Advanced search
2272476 Posts in 66752 Topics by 16945 Members
Latest Member: Zula
* Home Help Arcade Search Calendar Guidelines Login Register
+  blonde poker forum
|-+  Community Forums
| |-+  Betting Tips and Sport Discussion
| | |-+  Mathematics and Betting Thread
0 Members and 1 Guest are viewing this topic. « previous next »
Pages: 1 2 3 [4] 5 6 7 Go Down Print
Author Topic: Mathematics and Betting Thread  (Read 23485 times)
arbboy
Hero Member
*****
Offline Offline

Posts: 13285


View Profile
« Reply #45 on: March 17, 2014, 04:59:05 PM »


The thing is though that a "perfect" arb bet should be a perfect bet to keep.  Arbing is just a tool to reduce variance that comes at a cost.

The solution might be to have a process for time pressure situations eg look at the correct score market for the TV high liquid matches.  Or even just do a shout out in the thread for bets at 10s+ same price in liquid betfair markets.

The perfect arb bet is to back a 5/1 shot at 11/2 and lay it at 9/2.  ie both bets individually are both value.  With regard to my 100/1 'first scoring play in the superbowl' i backed 100/1 and laid it at 55/1 on bf with 2 of the £25 free bets i had.  I have no idea whether the 100/1 is value or laying 55/1 on bf is value.  I would imagine both trades are value trades and i can make them both without any risk to myself and no swings to worry about.  I would imagine the correct price is somewhere between the two and at the same time convert a £25 free bet into actual cash with a profit on top with no risk at all.
« Last Edit: March 17, 2014, 05:16:03 PM by arbboy » Logged
doubleup
Hero Member
*****
Offline Offline

Posts: 7049


View Profile
« Reply #46 on: March 17, 2014, 05:14:27 PM »


point taken but usually the error is on one side and in the context of this discussion we are usually looking for a bet that is as close to ev neutral as possible.
Logged
BorntoBubble
Hero Member
*****
Offline Offline

Posts: 5893



View Profile
« Reply #47 on: April 02, 2014, 09:01:50 PM »

Coral had a mobile offer today of 2/1 for hazard or oscar to score anytime.

The best prices were 5/1 and 4/1 I think. So if i just backed them at the best prices I get

£8 on at 4/1 and
£10 on at 5/1
I win £40 if either score and £80 if both score.

Yet if i place £18 with coral i get £36? Have I got the maths right here and this is a shocking offer? Or is there something im missing.

If the odds of two individual events are priced at 5/1 and 4/1 what is the calculation for working out either or happening is that using that nCr calculation? I probably should know this but my brain is doing a brain fart.

Why if these calculations are correct to bookies send out these offers if they are horrific?
Logged

"ace high"

http://plascolwyn.co.uk/ - 9 Bed Self Catering Holiday let in Snowdonia, North Wales Pm for more details.

Follow me on Twitter https://twitter.com/CalMorgan7
rfgqqabc
Hero Member
*****
Offline Offline

Posts: 5483


View Profile
« Reply #48 on: April 02, 2014, 09:07:35 PM »

Coral had a mobile offer today of 2/1 for hazard or oscar to score anytime.

The best prices were 5/1 and 4/1 I think. So if i just backed them at the best prices I get

£8 on at 4/1 and
£10 on at 5/1
I win £40 if either score and £80 if both score.

Yet if i place £18 with coral i get £36? Have I got the maths right here and this is a shocking offer? Or is there something im missing.

If the odds of two individual events are priced at 5/1 and 4/1 what is the calculation for working out either or happening is that using that nCr calculation? I probably should know this but my brain is doing a brain fart.

Why if these calculations are correct to bookies send out these offers if they are horrific?

The word boost gets people excited. Lol maffs etc.
Logged

[21:05:17] Andrew W: you wasted a non spelling mistakepost?
[21:11:08] Patrick Leonard: oll
BorntoBubble
Hero Member
*****
Offline Offline

Posts: 5893



View Profile
« Reply #49 on: April 02, 2014, 09:12:57 PM »

Coral had a mobile offer today of 2/1 for hazard or oscar to score anytime.

The best prices were 5/1 and 4/1 I think. So if i just backed them at the best prices I get

£8 on at 4/1 and
£10 on at 5/1
I win £40 if either score and £80 if both score.

Yet if i place £18 with coral i get £36? Have I got the maths right here and this is a shocking offer? Or is there something im missing.

If the odds of two individual events are priced at 5/1 and 4/1 what is the calculation for working out either or happening is that using that nCr calculation? I probably should know this but my brain is doing a brain fart.

Why if these calculations are correct to bookies send out these offers if they are horrific?

The word boost gets people excited. Lol maffs etc.

Just it was so bad (using my maths) I assumed i got it wrong.

Sad that im sat here looking at maths on betting rather than getting a maths degree.
Logged

"ace high"

http://plascolwyn.co.uk/ - 9 Bed Self Catering Holiday let in Snowdonia, North Wales Pm for more details.

Follow me on Twitter https://twitter.com/CalMorgan7
Tal
Hero Member
*****
Offline Offline

Posts: 24352


"He's always at it!"


View Profile
« Reply #50 on: April 02, 2014, 11:20:04 PM »

You mean £8 at 5/1 and £10 at 4/1, right?
Logged

"You must take your opponent into a deep, dark forest, where 2+2=5, and the path leading out is only wide enough for one"
BorntoBubble
Hero Member
*****
Offline Offline

Posts: 5893



View Profile
« Reply #51 on: April 02, 2014, 11:28:25 PM »

You mean £8 at 5/1 and £10 at 4/1, right?


Yeah i did!
Logged

"ace high"

http://plascolwyn.co.uk/ - 9 Bed Self Catering Holiday let in Snowdonia, North Wales Pm for more details.

Follow me on Twitter https://twitter.com/CalMorgan7
doubleup
Hero Member
*****
Offline Offline

Posts: 7049


View Profile
« Reply #52 on: April 02, 2014, 11:32:36 PM »

with this kind of bet just work out how much you need to bet to return £100 on both bets so £20 @ 4-1 gives you a £100 return and £16.67 @ 5-1 gives you a £100 return.

If you add them together you get £36.67 bet will get you £100 return if either of them win -- in comparison to £33.33 bet @ the 2-1 getting you same £100 if either win.

So the 2-1 is better as you only lose £33.33 if the bet fails and you get the same return if it wins.

Logged
doubleup
Hero Member
*****
Offline Offline

Posts: 7049


View Profile
« Reply #53 on: April 03, 2014, 12:33:49 AM »

oops misread your problem - obv a bad offer as you can get the double payout
Logged
doubleup
Hero Member
*****
Offline Offline

Posts: 7049


View Profile
« Reply #54 on: April 03, 2014, 11:13:29 AM »


ok having another look at it with fresh eyes, think I have it now....


Your method is wrong because I win £40 if either score isn't correct as you haven't deducted the loss from the other bet.

ie when you win the £8 at 5-1, you lose the £10 at 4-1, so you actually just win £30.

Back to my above post comparing the returns


you get £36.67 bet will get you £100 return if either of them win with the two separate bets  in comparison to £33.33 bet @ the 2-1 getting you same £100.


I had a mess around with a Poisson calculator (assuming that the 5-1 and 4-1 odds are accurate) to try and find an approximate % where both players score and it seems to be about 3% or so

So if we say roughly 66% neither scores, 31% either player scores and 3% both score

For our stake of £36.67 we get

nil 66%

£100 31% = £31

£200 3% = £6

So a return of £37

If we put the same £36.67 on the offer @ 2-1 our return would be

£110 34% = £37.40


So after all that really not much in it.



Logged
JaffaCake
Hero Member
*****
Offline Offline

Posts: 1884



View Profile
« Reply #55 on: April 28, 2014, 05:47:29 PM »

I am gonna reread this thread but if it hasn't been covered, this is what I posted on TfT:

"Red/Argue....how do u decide what's bes, 10/11 at one total or evens at a point higher or whatever. Is there proper maths behind it or is it a feel thing? Same for if say we can back a horse at 16/1 ew with 4 places or 14/1 ew with 5 places (or whatever).

Is that a question best asked on the maths thread?"

Also wanted to add, quite often I look at basketball handicaps, one firm will be 10/11 +6.5, another evens +7, another 8/11 +10 etc etc
Logged
arbboy
Hero Member
*****
Offline Offline

Posts: 13285


View Profile
« Reply #56 on: April 28, 2014, 05:49:38 PM »

Stu is def your man for the maths side of buying points etc in nba. 
Logged
redarmi
Hero Member
*****
Offline Offline

Posts: 5232


View Profile
« Reply #57 on: April 28, 2014, 06:30:36 PM »

Posted this in TFT:

"The NBA are fairly easy to work out.  Each individual point is likely to land a certain amount of time so has a value.  In the NBA for a regular pointspread most half points are worth about 0.05 in decimals.  So-3 2.0 is about the same as -3.5 2.05.  They differ slightly as some pointspreads are more likely to fall and I have charts for them but as a rule 0.05 is fine.

As for horseracing places - feel is better.  There is some very heavy academic work on how likely a horse is to place and nobody has "solved" it as such but if you look at enough of them you get a reasonably good feel.  An okay rule of thumb is if you turn the prices into percentages so in the case you said.  The place price at 14/1 is 7/2 (14/4) or 22.22% for 5 places.  For 4 places it is 4/1 (16/4) or 20%so they are effectively they are saying there is a 2.22% chance of your horse coming 5th (22.22%-20%) which is about a 45/1 shot so ask yourself would I back this horse to come fifth at 45/1?  That sounds like value to me so I would take the extra place and even if I only thought it was fair value I would take it because the extra place reduces my variance.  Does that make sense?"

I didn't actually address your question on nba totals though.  It is probably about 0.04 for NBA totals as a rule.  If you have a pinnacle account then log into your account and look to see what they charge and they are pretty much spot on.  If you find a book offering much different to what pinnacle offer then that book is wrong and you have a bet.  If you want the NBA pointspreads I have a chart I did one time but I don't think I ever did the totals because they don't vary as much so 0.03-0.04 works well.
Logged

Longines
Gamesmaster
Hero Member
*****
Offline Offline

Posts: 3798


View Profile
« Reply #58 on: April 29, 2014, 06:56:55 PM »

I've been thinking about this spread betting question and it's making my head hurt, wonder if anyone can help.

On average, 0.22 penalties are scored in each champions league game so if it was a normal bet then in theory we fill our boots when offered 5/1 or better on a penalty being scored.

Assuming the time that the penalties are scored is random and evenly spread throughout the 90 minutes* how do you determine the buy or sell point at which a bet is strictly mathematically +EV?


*big assumption, I know.
Logged
doubleup
Hero Member
*****
Offline Offline

Posts: 7049


View Profile
« Reply #59 on: April 29, 2014, 07:34:30 PM »

4-1 or better surely

[/nitmanship]


edit

although it occurs to me that some matches have more than one penalty, so really the relevant stat is the % of matches with penalties

« Last Edit: April 29, 2014, 07:37:33 PM by doubleup » Logged
Pages: 1 2 3 [4] 5 6 7 Go Up Print 
« previous next »
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!
Page created in 0.124 seconds with 21 queries.