Bookmakers Table of Percentages

[timtam]

There is an ad in the Daily Racing Form which highlights the fact it actually teaches the Bookmakers Table of Percentages. Its supposed to be 5th grade math and EVERY professional can recite this table. It is supposed to be the only publication that teaches it and its for value wagering and betting strategies.

I know there are alot of smart handicappers that read this board and was wondering if anybody can recite the Bookmakers Table of Percentages and is it as valuable as the ad states. Also for $50 you get a copy of a magazine method. Just curious but if it can help making better wagers it might help out a few novices like myself.

[NoDayJob]

Originally posted by timtam
There is an ad in the Daily Racing Form which highlights the fact it actually teaches the Bookmakers Table of Percentages. Its supposed to be 5th grade math and EVERY professional can recite this table. It is supposed to be the only publication that teaches it and its for value wagering and betting strategies.

I know there are alot of smart handicappers that read this board and was wondering if anybody can recite the Bookmakers Table of Percentages and is it as valuable as the ad states. Also for $50 you get a copy of a magazine method. Just curious but if it can help making better wagers it might help out a few novices like myself.

A BETTING PERCENTAGE TABLE CAN BE CONSTRUCTED AS FOLLOWS:

((- odds) / (odds + 1) + 1) * 100

5/2 = ((-2.5) / (3.5) + 1) * 100 = 28.57143%

1-10 = ((-.1) / (1.1) + 1) * 100 = 90.9091%

12-1 = ((-12) / (13) + 1 * 100 = 7.69231%

50-1 = ((-50) / (51) + 1) * 100 = 1.96079%

A bookmaker would include his vigorish percentage.

NDJ

[Tom]

http://www.icapper.com/odds_table.html

[kenwoodallpromos]

Great post Tom! That is why I love the PA boasrds!

[JustMissed]

What is just as much fun is to go to your charts and convert the decimal odds back to whole number odds(odds to a dollar).

Good practice if you like numbers.

JM

[NoDayJob]

Originally posted by JustMissed
What is just as much fun is to go to your charts and convert the decimal odds back to whole number odds(odds to a dollar).

Good practice if you like numbers.

JM



P = Percentage

O = Odds

P = ((-0) / (O + 1) + 1) * 100

O = (100 / P) - 1

Odds = 9/2

P = ((-4.5) / (5.5) + 1) * 100 = 18.18182%

O = (100 / 18.18182) - 1 = 4.4999994

NDJ

[OTM Al]

This formula can actually be simplified a bit to

Percentage = (1/(1+0dds))

(Multiply by 100 if you don't think of percents in decimal terms)

The key here though is to remember what this percentage is. It is the percentage of the win pool in question accounted for by that particular horse, not percentage of total win bets on that horse nor can it truely be considered a win probability as it adds up to over 100%. Run this through the final odds at Belmont for example and you'll get 117% every time because of takeout of 15%. If you want to make a calculation for % of total bet or a win probability proxy, then you must multiply the above by 1-T where T is the fraction removed on takeout (T=.15 in the Belmont example).

[JustMissed]

NDJ, what I was talking about was converting the decimal odds as shown on a printed chart to a tote board type fractional odds.

Easy of course 3.00 is 3/1. 4.0 is 4/1, etc.

But what about 2.80, 3.30, 4.30, 34.50 for example.

3.30 is the same as 33/10. But there is no tote board equivalent to 33/10.

I may be wrong but aren't most tote board odds denominators 1,2,5,10 or 99?

You see the point. If a horse goes off at 3.30, pays $8.60, what was the fractional odds? I guess you gotta say 33/10.

JM

[so.cal.fan]

I know you are a scientist/mathematician, so please excuse a dumb question from a mathematically impaired lady.

Does a bettor get unfair odds, as a rule, in shorter fields?
I ask because a few of my friends maintain that they do.
The shorter the price, the more likely that you will get unfair odds, even higher takeout, due to breakage.

[NoDayJob]

Originally posted by so.cal.fan
I know you are a scientist/mathematician, so please excuse a dumb question from a mathematically impaired lady.

Does a bettor get unfair odds, as a rule, in shorter fields?
I ask because a few of my friends maintain that they do.
The shorter the price, the more likely that you will get unfair odds, even higher takeout, due to breakage.

I am neither scientist nor mathematician so I'll leave the answer to your question to the statisticians.

NDJ

[so.cal.fan]

Sorry, NDJ.....I've been reading your posts for years, and I just thought you must be a math guru.....no matter.....what would you guess the answer to be?

[NoDayJob]

Originally posted by so.cal.fan
Sorry, NDJ.....I've been reading your posts for years, and I just thought you must be a math guru.....no matter.....what would you guess the answer to be?

The lower M.L odds would be over bet most of the time.

NDJ

[so.cal.fan]

I agree. Okay......what if we confined our bets to selections that are not one of the first two choices on the morning line?
Overlay? Or not?
I have long thought this was a workable alternative to complex charts and advanced math in regards to getting square value.
However.......I am sure no expert, and have never done research to prove or disprove my theory.
Now, I have only considered this angle on So. Calif. racetracks.
We have good morning line makers........so when we challenge their opinion with a third or higher morning line selection......we usually, but not always, get an overlay....or so it seems.

[NoDayJob]

Originally posted by so.cal.fan
I agree. Okay......what if we confined our bets to selections that are not one of the first two choices on the morning line?
Overlay? Or not?
I have long thought this was a workable alternative to complex charts and advanced math in regards to getting square value.
However.......I am sure no expert, and have never done research to prove or disprove my theory.
Now, I have only considered this angle on So. Calif. racetracks.
We have good morning line makers........so when we challenge their opinion with a third or higher morning line selection......we usually, but not always, get an overlay....or so it seems.

It seems to me, you'd need to know what percentage of the time your selection wins, in order to make a determination whether the wager is an overlay. If you keep records, why not look at the win percentages of your top two selections and use that as a base to determine whether you have an "over" or underlay. My top selection has better than 1 in 3 chances of winning and my 2nd choice has better than 1 in 4 chances, so it's fairly easy for me to determine an overlay.

NDJ

[socantra]

Originally posted by JustMissed
NDJ, what I was talking about was converting the decimal odds as shown on a printed chart to a tote board type fractional odds.

Easy of course 3.00 is 3/1. 4.0 is 4/1, etc.

But what about 2.80, 3.30, 4.30, 34.50 for example.

3.30 is the same as 33/10. But there is no tote board equivalent to 33/10.

I may be wrong but aren't most tote board odds denominators 1,2,5,10 or 99?

You see the point. If a horse goes off at 3.30, pays $8.60, what was the fractional odds? I guess you gotta say 33/10.

JM

Normally would be posted at the next lowest fractional equivalent. 2.80 would be 5/2, 3.30 would be 3/1, 4.30 would be 4/1 and I suppose 34.50 would be 30/1. If the tote board shows 3/1 at the close of betting, you will get at least $8.00 back on your $2.00 bet. If it closes at 7/2 you will get at least $9.00. Is that the question?


socantra...

[andicap]

Originally posted by NoDayJob
It seems to me, you'd need to know what percentage of the time your selection wins, in order to make a determination whether the wager is an overlay. If you keep records, why not look at the win percentages of your top two selections and use that as a base to determine whether you have an "over" or underlay. My top selection has better than 1 in 3 chances of winning and my 2nd choice has better than 1 in 4 chances, so it's fairly easy for me to determine an overlay.

NDJ

Is that at all odds?
In other words, do your top choices at 3-1 win a lot more than when your top choice is 6-1? Or are the final odds irrelevant as to the chances of your top two choices?

[NoDayJob]

Originally posted by andicap
Is that at all odds?
In other words, do your top choices at 3-1 win a lot more than when your top choice is 6-1? Or are the final odds irrelevant as to the chances of your top two choices?


26% are 0.00 to 2.99-1, 26% are 3-1 to 4.49-1, 39% are 4.5 to 14.99-1 and 9% are 15-1 or greater---based on M.L odds only.

NDJ

[JustMissed]

Originally posted by socantra
Normally would be posted at the next lowest fractional equivalent. 2.80 would be 5/2, 3.30 would be 3/1, 4.30 would be 4/1 and I suppose 34.50 would be 30/1. If the tote board shows 3/1 at the close of betting, you will get at least $8.00 back on your $2.00 bet. If it closes at 7/2 you will get at least $9.00. Is that the question?


socantra...

Thanks Socantra, That is what I was talking about.

I think so much in terms of fractional odds that I subconciously try to convert the decimal odds shown in the charts and pp's.

Always amusing at the track when the old guys sitting by me hit a 2/1 shot that pays $6.40 instead of the $6.00 they were expecting. They go on for hours about that extra $.40 they got as if the track made a mistake. Keeps them entertained.

JM