Past posting

[Robert Fischer]

Originally Posted by JerryBoyle

Yeah, in my opinion, it should be phrased such that the jackpot is triggered when there's a sole owner of a single combination, regardless of whether the combo is merged w another combo, or whether there's more than the minimum bet on the combo. Even if you bet the same combo twice, if you're the sole owner of a ticket(s) with the combo, you should get the jackpot. That seems to be in the spirit of it, and it makes the math easier .

As for the equation for kelly, considering all dependent outcomes and their impact on payoff, it's fairly straightforward:



N = number of combinations
W = total money bet into the pool prior to proposed bets
Q = 1 - track take
w_i = current money bet on combination i
b_i = proposed bet on combination i
p_i = model's estimate of combination i winning
I = starting bankroll
r = rebate % for the type of pool

The equation gives the expected change in logarithmic wealth for a given set of bets. You'd then maximize that equation with respect to a series of bets. Solving it simply in python using scipy's minimize function is easy. However, solving it quickly for large pools is not trivial. In my experience, more complex solutions are required for anything more exotic than the exacta/daily double pools.


I should note that the equation is presented in a paper in Efficiency of Racetrack Betting Markets titled "Concavity Properties of Racetrack Betting Models" by J.G. Kallberg and W.T. Ziemba. I only modified it to include rebates.

love it.

and then there is kind of a 'game theory' part to trying to 'scoop the pool' of these 'jackpot' rules wagers.

The value of the most unpopular long shots of the sequence is significantly affected by whether they figure to be uncovered (or 'scoopable').

edit- and I like the addition of 'rebates'.
I usually consider 'carryover' under that umbrella. Consideration definitely applies in these types of wagers.

[JerryBoyle]

Originally Posted by Robert Fischer

love it.

and then there is kind of a 'game theory' part to trying to 'scoop the pool' of these 'jackpot' rules wagers.

The value of the most unpopular long shots of the sequence is significantly affected by whether they figure to be uncovered (or 'scoopable').

Yep, for sure. To be honest, I don't have the bankroll to bet the pools that have jackpots, so I haven't given it a ton of thought.

One way that comes to mind that doesn't include thinking about the game theory part is take whatever your market estimated payoff for a combination is and convert it to an implied probability. Then multiply that implied probability by the pool total to get the total expected $ wagered on a given combination. If the expected $ wagered is less than the minimum bet size, you could adjust the payoff to be the entire pool + the jackpot. A simple approach to allow for the fact that people will be hunting for bombs would be to increase the desired minimum expected $ wagered below which you assume the entire pool will be scooped.

I'm sure there's a more scientific approach, though

[dilanesp]

A more general observation about this subject:

I think a lot of horseplayers underappreciate the distinction between these four types of betting pools:

1. A pool where everyone has real-time information about the odds. (I.e., a win pool.)

2. A pool where everyone in theory has real-time information about the odds, but very few players do the math to take advantage of it. (I.e., place and show pools, exacta pools.)

3. A pool where real-time information available, but only before the first segment of the wager, and many players also ignore it. (I.e., daily double pools.)

4. A pool where no real-time information is available. (I.e., a trifecta, superfecta, Super High Five, or horizontal wager other than the daily double.)

First of all, (1) is obviously going to be the most efficient betting market. And (3) is going to present opportunities where a horse in the second leg is going to be bet differently in the win pool than in the double pool because of the lack of real-time information.

But also, when you are betting in type (4) pools, you have to do a lot of thinking about what the public is likely to bet and what combinations are likely to offer value or no value. And while I am sure the top players with their computers are doing this, it doesn't sound to me like ordinary horseplayers are.

An example of the sort of thinking I am critiquing is when someone likes an even money favorite and says "he offers no value in the win pool, so I am going to key him in the exotics" without even a whiff of analysis as to whether the horse will offer even less value in the exotics because other bettors are thinking the exact same way. You hear this stuff all the time.

[cj]

Not that I didn't already know this, but the one thing to be learned from all this is that if you are playing these jackpot pools with a small bankroll alone, good luck. You are simply feeding the whales.

[JerryBoyle]

Originally Posted by dilanesp

A more general observation about this subject:

I think a lot of horseplayers underappreciate the distinction between these four types of betting pools:

1. A pool where everyone has real-time information about the odds. (I.e., a win pool.)

2. A pool where everyone in theory has real-time information about the odds, but very few players do the math to take advantage of it. (I.e., place and show pools, exacta pools.)

3. A pool where real-time information available, but only before the first segment of the wager, and many players also ignore it. (I.e., daily double pools.)

4. A pool where no real-time information is available. (I.e., a trifecta, superfecta, Super High Five, or horizontal wager other than the daily double.)

First of all, (1) is obviously going to be the most efficient betting market. And (3) is going to present opportunities where a horse in the second leg is going to be bet differently in the win pool than in the double pool because of the lack of real-time information.

But also, when you are betting in type (4) pools, you have to do a lot of thinking about what the public is likely to bet and what combinations are likely to offer value or no value. And while I am sure the top players with their computers are doing this, it doesn't sound to me like ordinary horseplayers are.

An example of the sort of thinking I am critiquing is when someone likes an even money favorite and says "he offers no value in the win pool, so I am going to key him in the exotics" without even a whiff of analysis as to whether the horse will offer even less value in the exotics because other bettors are thinking the exact same way. You hear this stuff all the time.

A+ . Captures it perfectly. Only thing I'd add is you might be surprised by the efficiency of the win implied probability from the exacta pool relative to the win pool. I've found it's often even sharper.

[SG4]

Originally Posted by the little guy

There is absolutely nothing even remotely similar to this situation and what happened in the BC Pick-6 scandal. This is how the CAW players put in their Pick-6 wagers....each combination individually for different amounts. There is NOTHING unusual about this particular play.

This situation brought to mind the fix-six scandal in that a pick 6 was hit for multiple times by 1 player, and that a big longshot highlighted that it was one player hitting for many times whereas a continued string of lower priced horses & nobody would've been aware how much of the pool a single person scooped up. Like I said earlier, because the longshot in this case was in the 2nd leg that didn't really raise red flags to me as an actual nefarious situation, but I appreciate Del Mar coming out immediately & making public the bets used for these tickets as to alleviate concerns.


What I found most surprising & curious about this wager (not in a suspicious way!) is that a single player or team would put in that level of handle into a mediocre pool size. I get that various whales etc probably control a greater % of other pool sizes throughout the day, but given the effective takeout of Del Mar's jackpot pick 6, the small carryover in play & the costs of a $2 base wager, it just doesn't seem like a wagering strategy that would continue to pay dividends, rebates or not. But maybe that's why they're $140k richer today & I'm not.



It was also interesting to see how every ticket is put in individually...this really could leave them susceptible to a big jackpot miss at some point if late scratches are involved.

[classhandicapper]

Originally Posted by JerryBoyle

A+ . Captures it perfectly. Only thing I'd add is you might be surprised by the efficiency of the win implied probability from the exacta pool relative to the win pool. I've found it's often even sharper.

That's what I alluded to earlier.

Many years ago, when I liked a horse, I would look at the exacta pool to see if I could create better value by wheeling the horse on top and betting an amount on each combination that would net the same return. I was basically trying to turn an 2-1 shot into a 5/2 shot. Almost invariably the late money would bring the two pools into sync. That was well before the computer era. So obviously either other people were already trying to arbitrage some kind of edge manually going back decades or the pools were so efficient it it was just happening naturally. I figured out fairly quickly it wasn't worth the mental energy to calculate the bet sizes and try to get all those different bets in manually.

I also tried a fair value chart where if I liked 2 or 3 horses it would tell me the fair value for each exacta combination based on the win odds. Then I could theoretically just bet the exacta combos that looked like overlays. I found more combinations that looked attractive that way, but I hated leaving off certain tickets and the late money still corrected most of it.

With computers doing the work now, there must be very few inefficiencies given there were very few before computers.

[Jeff P]

Imo, the predictive value of exacta pools relative to win pools varies from one racing jurisdiction to another.

At NYRA tracks (AQU-BEL-SAR) where the exacta takeout is 18.5%, unless you are looking at races with tiny fields, the exacta pool will almost always be larger than the win pool. As a result (Imo) the exacta pool will likely be more predictive than the win pool.

At California tracks (DMR-GGX-SAX) where the exacta takeout is 22.68%, unless you are looking at races with exceptionally big fields - it's the opposite: The exacta pool will almost always be smaller than the win pool. As a result (Imo) the exacta pool will likely be less predictive than the win pool.

Carry on,


-jp

.

[classhandicapper]

Originally Posted by Jeff P

Imo, the predictive value of exacta pools relative to win pools varies from one racing jurisdiction to another.

At NYRA tracks (AQU-BEL-SAR) where the exacta takeout is 18.5%, unless you are looking at races with tiny fields, the exacta pool will almost always be larger than the win pool. As a result (Imo) the exacta pool will likely be more predictive than the win pool.

At California tracks (DMR-GGX-SAX) where the exacta takeout is 22.68%, unless you are looking at races with exceptionally big fields - it's the opposite: The exacta pool will almost always be smaller than the win pool. As a result (Imo) the exacta pool will likely be less predictive than the win pool.

Carry on,


-jp

.

That's a good insight, but either way I bet they wind up pretty close to in sync by post time.

The only place I've seen gross inefficiencies (and granted I don't play a lot of tracks) is at the California fairs where I like to bet on mule races. Sometimes the pools are ridiculously out of whack and stay that way. The problem is the pools are so small, there are also some dramatic swings where they end up way out of line but you wind up in the wrong pool at the end even though you were in the correct pool with a minute to go.

[GMB@BP]

Sounds like there may be some truth to the fact these large CW teams may have access to all the ticket combinations? I have no idea how legit this is.

Twitter

[dilanesp]

Originally Posted by GMB@BP

Sounds like there may be some truth to the fact these large CW teams may have access to all the ticket combinations? I have no idea how legit this is.

https://twitter.com/MervHuber/status...92367567081472

It has always been denied, but I have my suspicions.

[classhandicapper]

Originally Posted by GMB@BP

Sounds like there may be some truth to the fact these large CW teams may have access to all the ticket combinations? I have no idea how legit this is.

https://twitter.com/MervHuber/status...92367567081472

If that's true, some of the exotic pools may be tougher to beat than WPS, Exactas, and Doubles because at least with the latter everyone is in same position of seeing the payoffs. All the teams can do is computerize the calculations and submit the bets later. In the other pools we are playing blind and they have 20-20 vision.

I've fundamentally changed the way I play anyway.

In the end it always comes down to me thinking I have an insight on a horse or aspect of handicapping (positive or negative) that is not shared by a lot of people. If I do, I'm going to get a decent price. So I make the bet and don't worry so much about the late odds changes unless the horse in the 2-1 or 5/2 range. The more bad information out there the better.

[iamt]

If they were doing this, and I don't actually think they are, wouldn't that mean there would be more than one ticket on a combination like this one.


Surely all the smart teams could see an uncovered combination with 5 favorites and one bomb and throw a couple of dollars on it.

[AndyC]

Originally Posted by classhandicapper

If that's true, some of the exotic pools may be tougher to beat than WPS, Exactas, and Doubles because at least with the latter everyone is in same position of seeing the payoffs. All the teams can do is computerize the calculations and submit the bets later. In the other pools we are playing blind and they have 20-20 vision.......

It wouldn't be hard to put daylight on all of these pools.

[castaway01]

All of this stuff is really depressing. I don't care if it's "fair" or "legal", it's not worth battling against when there are so many other ways to gamble in the United States.