the x13 model

[formula_2002]

X13 is based on the concept that given "complete" information as possible to make an accurate decision, the bettor will try to beat those decisions by betting against them.

X13 uses the short to long odds bias and attempts to exploit it by playing the shortest possible odds in racing, the show pool.

On 12/6/05, I declared that x13 would be limited to fields of 9 or more.

Since that time, the show pool profits are 3.7%, without rebates.
924 races were reviewed, 102 were played.

The model's show pool won 75% of the time. (average win pool odds of 1.54-1)
The public’s show pool win % was 62%.(average win pool odds of 1.80-1).

Because I demand a small incremental odds analysis, at this point, I have no idea if this is a valuable system. On average odds, the x13 system wins exceed the public’s wins by over 2.5 deviations.

Is there another way to make a meaningful analysis?

[formula_2002]

I did a bit of incremental odds analysis on the above and found the following;
When the win pool odds are held to the range >=.5 to <=1.3 there were 40 system plays;
There was a 3% show pool profit
The system show pool won 83% of the time. (average win pool odds of .97-1)
The public’s show pool win % was 75%.(average win pool odds of .96-1).
That represents but 1.0 deviation . Not a good thing.

When the win pool odds are held to the range >1.3 to <=2 there were 41 system plays;
There was a 3% show pool LOSS
The system show pool won 70% of the time. (average win pool odds of 1.69-1)
The public’s show pool win % was 59%.(average win pool odds of 1.70-1).
That represents but 1.66 deviations. Not a good thing.

When the win pool odds are held to the range >2 there were 20 system plays;
There was a 18% show pool profit.
The system show pool won 75% of the time. (average win pool odds of 2.43-1)
The public’s show pool win % was 56%.(average win pool odds of 2.55-1).
That represents but 1.8 deviations. A bit better.

It's a whole different story when you do incremental odds analysis.

[JulieKrone]

At 75% bet them in parlays of two. And if you can up the win % into the 80's, so you can string 3-5 together at a time you will make a killing(will be like a steady paycheck), even if the flat bet roi is slightly in the red.

[formula_2002]

At 75% bet them in parlays of two. And if you can up the win % into the 80's, so you can string 3-5 together at a time you will make a killing(will be like a steady paycheck), even if the flat bet roi is slightly in the red.

The problem with parlays is, you don’t get the premium you are entitled to for winning consecutive events.

Best example is the daily double.

The first leg wins at 1-1, the second leg wins at 1-1

Your $2.00 parlay returns $8.00
Your total wager was $6. Your net is $2.00
You made a 33% profit.
Even without adjusting for the take-outs, the probability of the dd is.
.5x.5= .25 or 3-1 odds
a $6 bet should return $24.00. Your net should be $18.00. Your min. required profit is 300% on that single bet.

Joe M

[Turntime]

formula_2002, your math looks incorrect. A $2 parlay that brings $8 is a 300% return - the second 'bet' is implied. Or if you made 2 separate bets, the first $2 bet brings a profit of $2 and the second bet at $4 brings a profit of $4 for a return of 100%. Comparing the two is apples and oranges since in a parlay you are 'forced' to make the second bet where as with separate bets you have a choice.

[rokitman]

Is there anywhere online that you can play parlays?

[formula_2002]

formula_2002, your math looks incorrect. A $2 parlay that brings $8 is a 300% return - the second 'bet' is implied. Or if you made 2 separate bets, the first $2 bet brings a profit of $2 and the second bet at $4 brings a profit of $4 for a return of 100%. Comparing the two is apples and oranges since in a parlay you are 'forced' to make the second bet where as with separate bets you have a choice.
tt.
I know many only look at the original $2.00 investment, but to be correct, you must add your “re-invested dollars” to the original. Therefore your total investment is $6.

There is a story of the guy who goes to the racetrack with $2.00 and hits a cold pick 6 for $200,000.
He goes to Vegas and loses everything but the cost of an air line ticket home.
His wife meets his the door and she asks “Honey, how did you do today”. He replies I lost $2.00..

[Turntime]

Sounds like we're trying to solve one of those brain teasers that ends with "where is the missing dollar?". You can only lose $2 on the parlay. To say that you've invested $6 implies that you could actually lose $6, which is not the case. ROI is calculated as profit (or loss) vs. money bet.

[formula_2002]

formula_2002, your math looks incorrect. A $2 parlay that brings $8 is a 300% return - the second 'bet' is implied. Or if you made 2 separate bets, the first $2 bet brings a profit of $2 and the second bet at $4 brings a profit of $4 for a return of 100%. Comparing the two is apples and oranges since in a parlay you are 'forced' to make the second bet where as with separate bets you have a choice.

tt I want some of that implied money :cool:
I bet $2.00 in the 1st leg and win. I get $4.00 back.
I go back to the window and parlay my entire return and win again. I get back $8.00 . I only bet $2.00. and "implied" and additional $4.00 for a net investment of $2.00... yahoo!! :jump:

[Turntime]

If you bet a $2 parlay with a bookmaker and the first leg wins, there is no way to get at the theoretical $4. Total investment will always be $2. If you bet $2 to win and collect $4 your return is 100%. If you choose to parlay it onto another even money shot and it wins, you will collect $8. Total invested is $6, total profit is $6 for a return of 100%, not 33% as you stated.

[formula_2002]

If you bet a $2 parlay with a bookmaker and the first leg wins, there is no way to get at the theoretical $4. Total investment will always be $2. If you bet $2 to win and collect $4 your return is 100%. If you choose to parlay it onto another even money shot and it wins, you will collect $8. Total invested is $6, total profit is $6 for a return of 100%, not 33% as you stated.

You are correct about the 100% profit.
So committing to a parlay at the beginning of the 1st leg and winning both legs will return 300% profit while exercising the option “to parlay” should the 1st leg win will return 100% profit.
The difference could be considered the cost of the option..

[JulieKrone]

Is there anywhere online that you can play parlays?

You do it manually: gives you flexibility to up and pull some money back along the way if you wish, sorta like Round-Robining.

I would also encourage, for this type of betting, that betting exchanges be looked at: utilizing Lay(to lose) can get that winning percentage way up there, allowing longer parlay strings.

There's a manuscript floating around called "The Opponent Method" that is very insightul in trying accomplish this.

[formula_2002]

You are correct about the 100% profit.
So committing to a parlay at the beginning of the 1st leg and winning both legs will return 300% profit while exercising the option “to parlay” should the 1st leg win will return 100% profit.
The difference could be considered the cost of the option..


tt
Allow me to completely correct myself here.
In the dd example example without take-out, mathematically, the parlay in the win pool and the straight bet in the win pool should return the same.

Apparently, over the years, I lost site of that because I have always viewed the straight dd as a better bet over the parlay because of the inefficiency in dd pool. And that is a completely different subject.

[formula_2002]

At 75% bet them in parlays of two. And if you can up the win % into the 80's, so you can string 3-5 together at a time you will make a killing(will be like a steady paycheck), even if the flat bet roi is slightly in the red.

JK
I look at the parlay as a limited The Martingale system.
In the long term, it can not improve the results.
Assuming you have an edge, my testing has shown that flat bets perform better in the short term while kelly betting improves results in the long term.

[andicap]

There's a manuscript floating around called "The Opponent Method" that is very insightul in trying accomplish this.

Written by our own Dave Schwartz.

[JulieKrone]

JK
I look at the parlay as a limited The Martingale system.
In the long term, it can not improve the results.
Assuming you have an edge, my testing has shown that flat bets perform better in the short term while kelly betting improves results in the long term.

Normally, a super high win % makes me glance at the Opponent manuscript, low % pulls me towards the other manuscript: HMI, and away from Kelly.

Are you talking about a 75% win rate @ avg 1.5-1 odds($3.00)? Then Kelly is fine the; and we're basically agreeing(in a roundabout way)-- 6 of 1 / ½ doz. of another: I'd be parlaying, up & pulling up partially, & continuing those tiny series until that mini session is over. Some kind of progression is basically called for-- I'd never just flat bet, esp. at a high % range.

[JulieKrone]

Written by our own Dave Schwartz.

You mean there is a Nobel Laureate candidate in your midst?

[formula_2002]

I just reviewed additional out of sample races.

301 plays resulting in a 5% win pool profit,
4% place pool profit and a 1 1/2% show pool loss.
This, combined with the previous out of sample races posted here, is my personal best performance.