My sprogs have been very encouraging of me starting this blog, mostly because it means that they don’t have to listen to me – but they have no problem burdening complete strangers with that task. They don’t read my blog so you can imagine my surprise at our convo yesterday morning.
Thing 4: Mom, I have a topic for your new blog post.
Me: Yes?
Thing 4: Sports betting.
Me: You want me to write about combinatorial calculus?
Thing 4:
Me: How much did you lose?
Thing 4: Enough*
*Please don’t despair on his behalf – I pay his allowance, so I know how much he can lose… it is not worth fretting over.
My rule of thumb for the Things have always been that if you cannot talk about it, you shouldn’t be doing it in the first place. Math and science in our lives are mostly those things ‘not to be talked about’. We have convinced ourselves that we don’t understand it and that it is the domain of a handful of bright people, whilst in reality, we use it every single day, numerous times.
Remember the board game snakes and ladders? Think of sports betting as the math equivalent – it is a game of chance, but in sports betting it is also a game of probabilities.
When you flip a coin, you have a 50/50 chance of getting heads. In gambling, this is called even odds. When you flip the coin again, you still have a 50/50 chance of getting heads. Whatever you got on the first flip of the coin, does not affect the outcome of the second flip. Each flip has the same probability as the previous one.
No rule says if you flip a coin twenty times, you must get ten heads and ten tails. Yet, we know that if we flip a coin twenty times, we would get heads and tails – and the more times we flip the coin, the closer we will get to a 50/50 split between heads and tails. Probability statements apply to a series of events, but not to individual events. So next time some smart ass tells you about the law of large numbers, you’ve got this: the ratio predicted by the probability statement will be increasingly accurate as the number of events increases – ergo, you have a 50/50 chance of getting heads or tails on a coin flip and the more times you flip the coin the closer you will get to the 50 % split heads and tails.
So let’s do the math – because remember we are normalizing bringing math conversations into our everyday conversations:
Probability = {Number~of~Desired~Outcomes \over Number~of~Possible~Outcomes} or
Probability = {Number~of~Favourable~Outcomes \over Number~of~Possibilities} or
P = {f \t}
P here represents the probability of you getting the outcome you want, a favourable outcome (f) divided by the number of possibilities (t). No, I have not lost you – let’s replace values: I give you two dice and ask you what is the probability of you throwing a seven?
There are six sides to a dice and you have two dice, i.e. 6 x 6 = 36. You have a maximum of 36 different outcomes (t = 36).
How many combinations do you have that will add up to 7? 1 + 6, 2 + 5, 3 +4, 4 + 3, 5 +2, 6 + 1 – so there are 6 possible combinations that can add up to 7, i.e. f = 6.
Plug them into the equation: P = {f \ t} which means that P = {6 \ 36} and this provides an answer of P = 6
Plug them into the equation: P =
What you have just done, is work out the odds – 1 throw out of every six will give you a total of 7, the other 5 throws will not. In gambling, the statement above will read back to front, so you start with the odds against winning: The odds against throwing a seven is 5 to 1.
Thing 4 wants this blog post to help him win money, so the question then is do you need luck or skill? It depends on what you are betting on – if you are playing the lottery, I hope you have a lot of luck, but if you play Blackjack, you will need skill. Sports betting is somewhere in the middle.
The Bet and Beat website says a reasonable ROI on sports betting is 5 % – so although it can be fun, it is not a get rich quick scheme. Successful sports betting would require you to be a ‘subject specialist’ because unlike flipping a coin, the events here are not independent, but you need to look at them in ‘groupings’. Your two favourite teams are playing against one another on the weekend and they are pretty evenly matched, so either team can win. Each team has a 50 % chance of winning, so like flipping a coin, this would give you even odds. A day before the match, you learn that the top point scorer in the one team and the pivot around which they built their game plan, is injured and will not play on the weekend. Suddenly the odds of the other team winning is increasing – and this has nothing to do with math.
You need to understand the game to understand the impact of losing a specific player – and not all players will affect the odds in the same way. The variables are endless, e.g. you could be losing one of your best attacking players, but you have quite a solid attacking substitute on the bench, so it will affect the odds, but not as bad as if you only had good defenders on the bench. The odds are affected not only by what you take away but also by what you add.
Sports betters will run any kind of odds and with big data sets freely available on the internet, you can build your strategy on what will influence the odds. Player x doesn’t travel well, so he is worth less in away games. Team Z cannot play in the rain, so we need to look at the weather forecast before placing our bets.
Having said all this, here are two bits of advice: systems and strategies can fail and don’t bet on your favourite team!
Big on Sports, a website on betting news and odds, ran some betting simulations. They selected the five most popular betting strategies and tracked their success over 500 bets. The most profitable betting methods were proportional betting and fixed amount betting.
In proportional betting, you bet a portion of your funds and then increase your bets by that same percentage after each win. Thing 4 has R1 000 (in his dreams, but this is a blog post, so let’s go with that) and he bets R100 (10 %) and wins R200. He will decide on his next wager by doing the following: R1 000 (his original bet) + R200 (his winnings) = R1200 x 10 % (his original betting percentage) = R120. Your winnings will increase quicker than if you bet R100 every time and your losses will slow down (fixed amount betting). [Just for interest, the team bet USD1 000 with a 55 % probability of winning each bet – they made USD19 275 using the proportional betting, USD6 600 using fixed amount betting and lost everything on the other methods before they got to 500.]
This is all lots of fun and easy to explain – as long as life doesn’t happen… Know your sport, know your players, know the statistics and make sure you know how your favourite team performs in the rain!
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