Do Bettors get it right?

[Canadian]

Just a general question for those who track such things. Do bettors generally get it right? I know the favorites win at a higher rate then the 5 th favorite. But do 10-1's win at a 10-1 rate (well, take out adjusted, I should probably ask does a 10-1 win at a 12-1 rate). How acurate is the odds board?

[shouldacoulda]

The odds on the tote board are with respect to payout. It is determined by the players placing wagers. In reality it has to do with the public's perception of who will win. It isn't the horses actual odds of winning the race. Considering favorites win 1/3 the time that means they are wrong 2/3 of the time.

[thaskalos]

Not only do the bettors as a whole generally get it right...they are nothing short of amazing in their accuracy.

Studies based on hundreds of thousands of races have reveiled that the favorites win the most races, the second favorites win the second most, the third favorites win the third most, etc...all the way down the line.

[cnollfan]

Also, the longshots get bet heavier than they should. So while the public's ordinal ranking of horses is accurate, those at the favorite end of the spectrum tend to a return on investment of - 10%, outperforming the track take of about 18%, while those at the longshot end tend to a return on investment of - 30%.

[Canadian]

The odds on the tote board are with respect to payout. It is determined by the players placing wagers. In reality it has to do with the public's perception of who will win. It isn't the horses actual odds of winning the race. Considering favorites win 1/3 the time that means they are wrong 2/3 of the time.


But that's kind of what I asked. Your just trying to tell me to word it a different way.

All the horses odds should add up to 100% (after factoring for takeout). Would they not? Meaning a 1-1 would have a 50% chance of winning, a 10-1 would have a .... would have a .. well what ever it works out to be.

But I am wondering do horses win at the rate as shown on the odds board?

[misscashalot]

But that's kind of what I asked. Your just trying to tell me to word it a different way.

All the horses odds should add up to 100% (after factoring for takeout). Would they not? Meaning a 1-1 would have a 50% chance of winning, a 10-1 would have a .... would have a .. well what ever it works out to be.

But I am wondering do horses win at the rate as shown on the odds board?
Yes

[shouldacoulda]

But that's kind of what I asked. Your just trying to tell me to word it a different way.

All the horses odds should add up to 100% (after factoring for takeout). Would they not? Meaning a 1-1 would have a 50% chance of winning, a 10-1 would have a .... would have a .. well what ever it works out to be.

But I am wondering do horses win at the rate as shown on the odds board?

If you mean the absolute mathematical probability of the horse to win the race then no, that is not what the tote board represents.

[Canadian]

If you mean the absolute mathematical probability of the horse to win the race then no, that is not what the tote board represents.


But doesn't it though? Maybe we're just getting caught up in semantics. If 5% of all money bet is on a given horse, do these horses win at a 5% rate over time.

Obviously not all 20-1's are equal as good handicappers know. Again it was just and overtime question.

[lamboguy]

what a question. i couldn't answer this one in a million years.the only thing that i can compare parimutual racing with is equity market trading. as in the equities markets, the market is the final arbitrator. in racing, the toteboard is the final arbitrator.

[Robert Goren]

I seen several studies on this. If you bet just the horse at a given odds you will aways lose money. The lower odds the less money you lose. If you were to bet 100,000 random horses at 4/5, you would lose less money that if you bet 100,000 random horses at 20/1. Not all 20/1 horses are created equal, but then nether are 4/5 horses. There is a ton of math that can explain that, but it will give you a headache.

[Robert Fischer]

the boring answer = by definition of the parimutuel system, the public will have a Value equal to
1.00 - the track take.

EXAMPLE (@20%TAKE)
VALUE = 1.0 - .20 = $0.80 = 20%loss

[shouldacoulda]

But doesn't it though? Maybe we're just getting caught up in semantics. If 5% of all money bet is on a given horse, do these horses win at a 5% rate over time.
No. It doesn't work that way.

[Canadian]

No. It doesn't work that way.


Do you have a number from so many races over a given amount of time that you can tell the rate at which horses recieving 5% of the money win @?

[acorn54]

in william quirin's book, computer studies winning at the races, he devotes a chapter to where he documented public odds in relation to the horses chances of winning. the conclusion drawn from his study was that yes, over time horses win according to their odds. there was a slight over bet bias on longshot horses in the 20-1 and higher range and a slight underbetting bias in the very low odds range, but overall yes horses win according to their odds over time.

[WinterTriangle]

Not only do the bettors as a whole generally get it right...they are nothing short of amazing in their accuracy.



How is being wrong about the favorite 2/3 of the time amazingly accurate?

[Canadian]

How is being wrong about the favorite 2/3 of the time amazingly accurate?

because there is more then 3 horses in most races.

[Stillriledup]

in william quirin's book, computer studies winning at the races, he devotes a chapter to where he documented public odds in relation to the horses chances of winning. the conclusion drawn from his study was that yes, over time horses win according to their odds. there was a slight over bet bias on longshot horses in the 20-1 and higher range and a slight underbetting bias in the very low odds range, but overall yes horses win according to their odds over time.

Longshots are overbet, this is correct. Take a look at the Ky Derby. In a 20 horse field, there should be a horse who is 100-1 but there hardly ever is.

I actually think that there could be some horses who are 1-5 and 2-5 that present the greatest overlays. Most horseplayers don't have sportsbettors mentality, they're used to seeing a 5 dollar horse as a very short price, but in sportsbetting, most bets are 9 to 10 or four and a half to five. Sports bettors have no problem betting a -330 favorite. The Lakers tomorrow are a -330 favorite, which works out to about a 1-5 shot. Plenty of people are betting on the Lakers and not thinking twice that they're betting on what amounts to a 1-5 shot (not exactly, but close)

[Overlay]

Just a general question for those who track such things. Do bettors generally get it right? I know the favorites win at a higher rate then the 5 th favorite. But do 10-1's win at a 10-1 rate (well, take out adjusted, I should probably ask does a 10-1 win at a 12-1 rate). How acurate is the odds board?

In the aggregate over time, the public is remarkably accurate in setting odds. However, it does not have that same degree of accuracy for each horse in each race. Being able to detect instances where the public has underestimated the winning chances of specific horses or combinations in individual races creates favorable wagering situations.

[Roghaltz]

As others have noted, favorites tend to be slightly under bet compared to their true odds and longshots over bet (not just in horseracing). There is a whole literature on the "favorite-longshot bias". See the following list:

http://favourite-longshot-bias.behaviouralfinance.net/

Roghaltz

[SMOO]

because there is more then 3 horses in most races.
:ThmbUp:

[Robert Goren]

I wonder with the advent of "whale" computer betting, which often lands on a short priced favorite, if the favorites are still under bet.

[SMOO]

I wonder with the advent of "whale" computer betting, which often lands on a short priced favorite, if the favorites are still under bet.
Also the place pools on chalks seemed to pay better in the past, seems like a load of money going there these days.

[kenwoodall2]

"Beat the Track [Paperback]
Ada Kulleck"
This book is an example of analyzing expected win % vs actual win % for various handicapping factors, like last out win. There are many others in here, a good book.

[kenwoodall2]

"Beat the Track [Paperback]
Ada Kulleck"
This book is an example of analyzing expected win % vs actual win % for various handicapping factors, like last out win. There are many others in here, a good book. Ainslie's book has stats on odds vs actuial win %.
Bettors get it right enough for me to say so!

[salty]

accuracy of the public at belmont Wednesday:

if you boxed the top 3 odds in an exacta

r1 2-4-1 miss

r2 4-6-5 big miss

r3 2-1-3 ex $8.70 tri $15

r4 3-1-2 ex $33.20 tri $84.50

r5 9-1-3 miss

r6 2-3-4 ex 19.80

r7 1-6-2 miss

r8 1-3-2 ex 32.80 tri $99

r9 1-8-2

exacta hit $94.50 bets cost 108 down only $13.50

tri hit $198.50 bets cost 108 up $90.50


Belmont last saturday:

r1 2-3-5 ex $53.50

r2 1-2-3 ex $10.80 tri $24.50

r3 2-3-7 ex $24.20

r4 2-1-3 ex $11.40 tri $15.00

r5 4-2-3

r6 4-3-2

r7 5-4-2

r8 7-5-1

r9 4-8-1

r10 6-1-5

[46zilzal]

no they don't have the patience to wait for the overlay.

[Jeff P]

Here's what I have for a recent 14 month data sample spanning all North American thoroughbred tracks broken out by the odds in half point increments:
Data Window Settings:
999 Divisor Odds Cap: None

SQL: SELECT * FROM STARTERHISTORY

Data Summary Win Place Show
Mutuel Totals 733552.40 740329.30 745392.10
Bet -984398.00-984398.00-984398.00
Gain -250845.60-244068.70-239005.90

Wins 60632 120631 177705
Plays 492199 492199 492199
PCT .1232 .2451 .3610

ROI 0.7452 0.7521 0.7572
Avg Mut 12.10 6.14 4.19
By: Odds Range

>=Min < Max Gain Bet Roi Wins Plays Pct Impact
0.05 0.50 -470.90 4388.00 0.8927 1480 2194 .6746 5.4760
0.50 1.00 -3374.70 23706.00 0.8576 5909 11853 .4985 4.0469
1.00 1.50 -5229.10 34614.00 0.8489 6683 17307 .3861 3.1346
1.50 2.00 -5860.00 39884.00 0.8531 6319 19942 .3169 2.5723
2.00 2.50 -6923.40 43006.00 0.8390 5648 21503 .2627 2.1322
2.50 3.00 -7360.90 42538.00 0.8270 4769 21269 .2242 1.8202
3.00 3.50 -7178.20 40282.00 0.8218 3954 20141 .1963 1.5937
3.50 4.00 -6478.90 37172.00 0.8257 3274 18586 .1762 1.4300
4.00 4.50 -6982.90 34058.00 0.7950 2613 17029 .1534 1.2456
4.50 5.00 -6054.30 30932.00 0.8043 2191 15466 .1417 1.1500
5.00 5.50 -6198.60 28494.00 0.7825 1804 14247 .1266 1.0279
5.50 6.00 -4806.30 26538.00 0.8189 1625 13269 .1225 0.9942
6.00 6.50 -5211.90 24610.00 0.7882 1351 12305 .1098 0.8913
6.50 7.00 -4383.90 22828.00 0.8080 1206 11414 .1057 0.8577
7.00 7.50 -3370.90 21248.00 0.8414 1094 10624 .1030 0.8359
7.50 8.00 -4111.00 19802.00 0.7924 904 9901 .0913 0.7412
8.00 8.50 -4955.70 18734.00 0.7355 751 9367 .0802 0.6508
8.50 9.00 -4476.00 18030.00 0.7517 701 9015 .0778 0.6312
9.00 999999.00-157418.00 473534.00 0.6676 8356 236767 .0353 0.2865



-jp

.

[thaskalos]

How is being wrong about the favorite 2/3 of the time amazingly accurate? In the history of our game...no individual player has ever been able to pick 33% winners, while making a selection in every race!

That's amazing!

[Robert Fischer]

In the history of our game...no individual player has ever been able to pick 33% winners, while making a selection in every race!

That's amazing!

not true. Unless you emphasize "every race" beyond a premium track over the course of a meet.

[thaskalos]

not true. Unless you emphasize "every race" beyond a premium track over the course of a meet. I'm sorry Robert...I don't understand your comment. Can you make it a little more clear please?

[cnollfan]

Thanks, Jeff. Excellent stats.

[Robert Goren]

"Beat the Track [Paperback]
Ada Kulleck"
This book is an example of analyzing expected win % vs actual win % for various handicapping factors, like last out win. There are many others in here, a good book. Ainslie's book has stats on odds vs actuial win %.
Bettors get it right enough for me to say so! For what it is worth, this book is 20 years old.

[BCOURTNEY]

The public determined odds are very accurate. This is because it is an ensemble of learners are more intelligent than any single individual. The sum of the parts is greater than the whole. This is also why it is hard to find positive expectation bet where the public has made an error. There is bias at both of the tails of the odds distribution. Any long term successful system has to account for this. It is different at every track. This can be calculated and accounted for and incorporated into a wagering strategy.

B

[SMOO]

Thanks, Jeff. Excellent stats.

What I found interesting was that it shows place & show ROI as higher than win ROI. How is this possible with the extra breakage?

[Steve 'StatMan']

If 5% of the money is on a given horse, he is less than 20/1 on the tote due to takeout, and generaly win much less than 5% of the time - how much less I do not know.