math ?

I posted this earlier at the offshore forum. If you keep records of your bets in Excel, you can add these lines and see can you win with parlays in a long run. I'll make new tracking system for my own purpose and modify this a little bit, but if you bet only lines -105 or -110 this is enough for you.

http://therxforum.com/6/ubb.x?a=tpc&s=100090022&f=988094022&m=49610692

Lets assume that we have a Joe Public betting on events and he goes as linemakers hope, winning 50% and losing 50% of his bets, always bets with a same stake and nothing but parlays. So he is losing money because there is the vig and a lot more vig with parlays.

What kind of odds he gets on straight wager when he's parlaying teams with a 20-cent line? In this case all teams have -110, just make it simple. With a 20-cent line bookmaker commission
is about 4.55%. 100-4.55 is 95.45% and this is how much bookmaker pays out on every wager. 100*0.9545=1.909 and Americans knows that as -110. Everytime you make 2 team parlay you have to calculate 0.9545*0.9545 and with 3 team parlay 0.9545*0.9545*0.9545 to solve the vig.

True odds on single wager with a 20 cent line and the original odd was -110 and Commission 4.55%.

2 team parlay -135 (Commission 8.90%)
3 team parlay -152 (13.04%)
4 team parlay -171 (17.00%)
5 team parlay -195 (20.77%)
6 team parlay -225 (24.38%)

If you think you can make money in a long run betting -225 on single wager when true odd is -110, 6 team parlay is perfect for you.

What a about dime line (10 cent line) -105/-105. Bookmaker commission is 2.4% with a dime line, so 100-2.4=97.6%. Calculating with a same way:

True odds on single wager with a 10 cent line and the original odd was -105 and the vig 2.4%.

2 team parlay -116 (4.74%)
3 team parlay -123 (7.03%)
4 team parlay -130 (9.26%)
5 team parlay -137 (11.44%)
6 team parlay -145 (13.56%)

A free tip for sportsbooks. Offer dime line on parlays, you will get more people betting parlays because they see -105 instead of -110, not a rising vig. You might have some smart people betting NCAA parlays, but with NFL and NBA you won't lose.

 

[Potter]

Isn't the real issue the difference between your estimation (subjective or otherwise) of the true probability of an event?

The size of the vig merely gives the bookmaker a larger or smaller margin for error.

If a bookie is unwise enough to continually go 6/4 heads & 1/3 tails(a very ungenerous margin for two outcomes),surely the fact that he is offering an extremely poor value price on the tails shouldn't negate the obvious value on the heads.

10/11 each of two would be a better margin from a punting point of view....but neither offers value.

Whether there's much value to be had in the nfl of course is another matter.

B,
there's a passable simulation program at www.high-adrenaline.com (no connection).It's set up for 3 way soccer bets but you can easily play about with the inputs to make it work for runs of 50 7/1 shots.

P.

 

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Isn't the real issue the difference between your estimation (subjective or otherwise) of the true probability of an event?
<HR></BLOCKQUOTE>

That's correct Potter, but there are a lot of people who don't estimate probabilities. It is a possible to be a good bettor without estimating percentages. This is for them and mainly for guys who would like to know how good they must be to make profit on parlays.

NOTE, BREAK EVEN PRICES ABOVE MIGHT BE FALSE, PLEASE CHECK THIS TOPIC

http://therxforum.com/6/ubb.x?a=tpc&s=100090022&f=988094022&m=30210803

Potter, could you give your opinion. Thanks

 

[Potter]

Hi Faceless,
I'll check the threads out.

My usual thoughts are that if you're offered odds of say 9/1 then your break even point is the odds expressed as a probability.

So you need to hit 10% of your 9/1 shots over the long term & to level stakes to break even.

Similarly for a 6/4 shot you need to hit 40%.

Specifically as regards parlays go to

http://about.bodog.com

click on "Frontlines" a read the november 2002 articles on parlays....I pretty much agree with what's said there.

All the best P.

 

[Bullchitna]

Thanks for the info guys, hopefully I can get a little more.

Can someone show me how to calculate a standard deviation for a 55% win rate on -110 bets and 3 team parlays that pay 6/1?

Also, I'm going to Vegas for labor day and plan on going to the gamblers bookstore. Any recomendations?

 

[jwunderdog]

I will get you a formula give me a couple of days , I don't have it handy.Most important factor is 50 bets is too small of sample size to use to be staitically significant.More on that when I have time. There are others here that probably have the formula handy. GL

 

[Bullchitna]

JDOG

I'm still waiting for that formula.

Anyways, I gave up on that thought of betting parlays, I've started betting NFL and am sticking to 1 unit/wager.

I wish I was smart enough to vary my bet size like ATX and Sixth Sense.

Good Luck To All