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Beating the bookies – how the online sports betting market is rigged

arxiv.org

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Re: Beating the bookies – how the online sports betting market is rigged

#61

Post by DennisP »

iopq wrote: post #41
downandout wrote: post #16

Earlier quoted context omitted.

the casinos simply ask you to leave if you win too much. I was actually backed off from the first place I went to after I learned how to count cards while I was losing . If the pit boss or dealers know how to count themselves and identify you as a counter, they want no part of it. In most cases, they'll either "flat bet" you (tell you that your initial bet is your maximum), or they'll tell you that you cannot play bl…

That's only if you vary your bet size. That's a definite tell.

How do you profit from card counting without varying your bet size?

Re: Beating the bookies – how the online sports betting market is rigged

#62

Post by darepublic »

DennisP wrote: post #61
iopq wrote: post #41

Earlier quoted context omitted.

That's only if you vary your bet size. That's a definite tell.

How do you profit from card counting without varying your bet size?

I guess you could always count from the sidelines and bet only in advantage spots. Not very practical I suppose but card counting in general seems pretty implausible these days

Re: Beating the bookies – how the online sports betting market is rigged

#63

Post by dogruck »

kirykl wrote: post #46
dogruck wrote: post #34

Earlier quoted context omitted.

Easier said than done. Suppose your book is balanced, and you have $25,000 on each side. Then a new bet comes in, size $250,000, on one side of your book -- what to do? Or, more simply, when you set your initial line, what do you do when a known sharp immediately wants action on one side?

Don’t honor the bet until you can balance it or limit it to an amount you can balance ?

The downside of that strategy is you will frustrate your customers and they will trade/bet elsewhere.

Re: Beating the bookies – how the online sports betting market is rigged

#64

Post by dogruck »

DVassallo wrote: post #54
dogruck wrote: post #34

Earlier quoted context omitted.

Easier said than done. Suppose your book is balanced, and you have $25,000 on each side. Then a new bet comes in, size $250,000, on one side of your book -- what to do? Or, more simply, when you set your initial line, what do you do when a known sharp immediately wants action on one side?

You buy the other side with another bookie. The risk is if the other bookies don't accept the full amount you want to hedge.

Yes, you open yourself up to counter party risk.

Re: Beating the bookies – how the online sports betting market is rigged

#65

Post by quickthrower2 »

ChuckMcM wrote: post #8

"Send enquires about this paper to our newly acquired private island in the Bahamas." :-) One of the most depressing things I realized when I learned to count cards, and confer upon myself a small but meaningful advantage in the game of Blackjack, was that the casinos simply ask you to leave if you win too much. That put an upper limit on the rate at which one could win. The folks who figure out slot machines have a…

I've worked for an online bookie. I've also worked for an outfit that bets (on horses mainly).

The online bookie will indeed ban or limit winning accounts or anyone they suspect of cheating or betting smartly. Anyone betting large amounts dumbly gets taken out to nice dinners etc.

The company that bets on horses bets using exchanges, because bookmakers would tend to kick them out. The abstract of this paper is pretty much 101 to those guys who do some advanced stuff I can't talk about to make predictions.

Good luck!

Re: Beating the bookies – how the online sports betting market is rigged

#66

Post by dogruck »

ElevenLathe wrote: post #36
dogruck wrote: post #34

Earlier quoted context omitted.

Easier said than done. Suppose your book is balanced, and you have $25,000 on each side. Then a new bet comes in, size $250,000, on one side of your book -- what to do? Or, more simply, when you set your initial line, what do you do when a known sharp immediately wants action on one side?

You open things up to select sharps earlier than the general public, with limits. They get the benefit of potentially better lines and you get the information benefit of what the pros think the fair price for any bet is, allowing you to adjust the line before allowing bets from the general public. That's how a lot of the offshore sportsbooks handle it, but it may not actually be legal to do so in Vegas. I don't actua…

One other factor is sometimes you actually are willing to take principal risk -- like when there are hoards of people willing to place bad bets on the local team -- you're willing to run an unbalanced book.

Re: Beating the bookies – how the online sports betting market is rigged

#67

Post by au_gambler »

A couple of suggestions to improve on this method.

The authors' regression left an intercept or 'adjustment term' of 3.4% - 5.7%. For a perfect bookmaker, this intercept term would be equal to the overround. The number calculated unfortunately averages that overround between different bookmakers and at different times (overrounds often decrease over time). It might be more effective to adjust for the actual overround of each market sampled, i.e. divide each price by the sum of the inverse of the prospects.

They appear to use a flat betting strategy, and the threshold to bet or not was selected based on profitibility. I was simplifying in another comment when I said profitibility should be the goal. In reality it's utility you should be optimizing for. Nobody wants a ultimately profitable system that reads like an EKG, they want a high sharpe ratio. The paper's results are actually very good here, but the trend could be lifted and stabilized further by betting proportionally to expectation, or by explicitly optimizing for such.

Re: Beating the bookies – how the online sports betting market is rigged

#68

Post by repsilat »

utnick wrote: post #15
mason55 wrote: post #12

Earlier quoted context omitted.

My guess is that it’s the manner by which they were winning. Thirty $50 bets per week over five months is over 500 bets. That’s not the long run but winning at an 8.5% ROI over that many bets is probably enough for the house to realize they’re somehow a winning player even if the stakes aren’t huge.

Sportsbooks in general don't mind winning players though, especially big ones. They make money off the vig and move odds to get equal money on each side of the bet so that they'll make money either way.

As someone who has worked in the sports betting industry, it depends a lot on the bookmaker. UK retail bookies hate anyone with any savvy, and will ban their accounts fast. Ditto "weird" betting that looks like it might be machine-run. Their business is taking old folks pensions from them.

OTOH, exchanges love all kinds of gamblers and won't ban you for winning any amount. "Smart money" Asian bookies will bet against anyone because their job is to have a better model than you. (Of course, there is a max bet on any offer, and the odds will move if you hit them hard enough.)

Also, everything in the abstract of this article is either old old news (strategy-wise) or plain wrong in light of the actual business of sports betting. "Implied odds" has been around forever, and real companies make real, consistent returns from arbitrage and "statistical arbitrage" on implied PDFs and have for years.

Re: Beating the bookies – how the online sports betting market is rigged

#69

Post by joosters »

seanalltogether wrote: post #42
GigabyteCoin wrote: post #11

Earlier quoted context omitted.

I used to use the betfair platform until it they blocked themselves from being viewed in Canada for some strange reason right after they were purchased by ladbrokes I believe it was. Anyways, after playing with them for a few years, I was horrified to learn about their 60% tax on consistent winners that they have dubbed a "premium charge". Found some sort of edge to exploit and reap profits? Betfair doesn't even care…

I'm confused, since betfair is an exchange aren't they just taking a cut of the action? Why would they add a heavy tax onto profits which would just drive heavy bettors away?

They do it because they can, and for many gamblers, Betfair is the only place they can realistically keep betting at. Other bookies will restrict winning gamblers’ stakes or refuse their bets, and other betting exchanges have far less liquidity than Betfair. So, successful punters on Betfair just have to grin and bear it...

n.b. The 20-60% ‘premium charge’ that Betfair inflict on long-term winners is different to their standard 2%-5% commission that they charge everyone for any net profit on a market. The premium charge is calculated weekly over a customer’s profit & loss. So its effect is not the same as if the commission was as high as 60% per bet. Like a tax, the PC won’t make a profitable gambler unprofitable, it ‘just’ means Betfair get to keep more of your profits.

It’s also worth pointing out that the standard commission (2-5%) can add up to far more than 60% of your winnings anyway. As no-one wins every bet they place, the commission will become a larger percentage of your net profit. For example, Betfair charge me 2% commission and I ‘qualify’ for their premium charge of 40% - but my betting patterns already result in over 40% of my gross profit going to Betfair :(

Re: Beating the bookies – how the online sports betting market is rigged

#70

Post by pgwhalen »

CPLX wrote: post #30
ChuckMcM wrote: post #8

"Send enquires about this paper to our newly acquired private island in the Bahamas." :-) One of the most depressing things I realized when I learned to count cards, and confer upon myself a small but meaningful advantage in the game of Blackjack, was that the casinos simply ask you to leave if you win too much. That put an upper limit on the rate at which one could win. The folks who figure out slot machines have a…

I my experience as a card counter they'd just swap in a new dealer who would count themselves and just shuffle whenever the count got really good. Ridiculously unfair and probably illegal but what are you going to do, complain?

Why would that be illegal?
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