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Is reading that book going to make me want to be a gambler? I find the maths fascinating but have a bit of an addictive personality so have never laid a bet and don't want to start. I'd love to understand it though
fredtc-
Is reading that book going to make me want to be a gambler? I find the maths fascinating but have a bit of an addictive personality so have never laid a bet and don't want to start. I'd love to understand it though
I had a long running interest in maths and read the book around the time I started doing an OU maths degree so it was perfectly timed. After working through loads of stuff and modelling it on years and years of previous data I found there was a small bit of money to be made, but the risk was huge, too big for me wanting to have stability for me and my family.
If anything it reinforced the idea that to win at gambling you either have to spot something no-one has (which is very unlikely) or just be lucky.
Same author has written some more up to date books, I've never read any of them though.
Greenbank
For example, take West Ham v Liverpool tomorrow.
Ladbrokes are offering 24/5, 18/5, 1/2 on West Ham, Draw, Liverpool respectively.
In decimal odds those are (24/5)+1 = 7.25, (18/5)+1 = 3.6, (1/2)+1 = 1.5
From there you can calculate the percentage chances: 100/7.25 = 13.8%, 100/3.6 = 27.8%, 100/1.5 = 66.7% (all to 1dp).
Now if you add them up you get 13.8% + 27.8% + 66.7% = 108.3%
That 8.3% helps ensure the bookies make a profit long term (even if they lose out on an individual event). In reality they offload most of the risk (trading with other bookies, betfair, etc) so that they pretty much guarantee that they'll make 1-2% regardless of the outcome of event.
Back in the early days of online betting you could often find bookies trying to compete with each other, and you'd find them offering better odds on different outcomes, such that you could spread a stake across multiple bookies on the different results and guarantee a profit. This is known as an arbitrage (or an arb for short).
For example, if most bookies were offering similar odds to the above but one bookie priced a West Ham win at 35/4 (so decimal odds of 9.75) the West Ham percentage is now 10.26% and the total percentages would add up to 98.7%. You could then bet a nominal £100 stake split as:
In all 3 cases you stand to win > £100 (your total stake). Only about £1.36 extra, but it's still a 1.36% profit on a single bet. Try finding a 1.36% guaranteed return in a single afternoon.
You'd sometimes find the arbs as good as 95%, which were a big payday. If you had £10000 to stake you'd earn £500 guaranteed "risk-free"* profit.
For a while, back in the early 2000s I made a good chunk of money each weekend doing this, but it didn't last long as I quickly got blacklisted from most of the local bookies, and the online bookies, plus it was a lot of work and a lot of stress (especially if the odds shortened before you'd laid all three bets). The outlier bets were usually only available to walk in customers in bookies, which meant a lot of traipsing around on a Saturday lunchtime.
The bookies eventually got wise to these and checked each others odds a lot more carefully which has pretty much eradicated the arb. The "odds boost" things do occasionally make it possible though.
After that I moved on to value betting as described in the bible of the time: https://www.waterstones.com/book/fixed-odds-sports-betting/joseph-buchdahl/9781843440192
That worked for a while (probably only ~£200 profit a weekend from a £5000 total stake) but was way riskier as a bunch of shit results could wipe you out. At least most of it could be done online and was less likely to trip the online bookies "betting system" alarms. I stopped because the margins were getting squeezed more and more and I could easily see gambling seriously fucking up my life so I stopped completely.
(Like most gambling things, I reckon the author of that book probably made more money writing about it and selling books than he did from the gambling itself. C'est la vie.)
#csb