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Not_Legal_Advice_Pod t1_izrwq9y wrote

So... good job by the bookmakers? Looks like over 18 or so years of doing this you'd be down fifty or so "points", which seems about right for any gambling.

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ikashnitsky OP t1_izrwvm4 wrote

Exactly. The big question is whether the surprising results at World Cups are random or systematic.

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Not_Legal_Advice_Pod t1_izrz4zo wrote

What that 2019 outlier? I don't think you can get to statistical significance on that one year. This looks like what I'd expect it to look like. You're probably better getting into the big data game by game statistics if you're looking for sings of tampering.

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FrankDrakman t1_izsrlcu wrote

Wasn't that Leicester's year? No one was picking them for anything, so every game would have been an upset, at least at the beginning.

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Niekio t1_izs2qpy wrote

I bet this would be the same when you bet in favor of the Odds. The house always wins!

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Eric1969 t1_izs76c1 wrote

On one hand, randomness has no memory. On the other hand, regression to mean is a thing.

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Mooks79 t1_izsp7u1 wrote

The latter is because of the former.

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Eric1969 t1_izsuqse wrote

I actually was debating this with a friend so vigorously that he coded a program to compare yhe wins of betting randomly or on lagging possible outcomes of a randomly generated number. Betting on lagging outcomes brought more wins.

Professional sports is not quite random though.

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Mooks79 t1_izsvfub wrote

>I actually was debating this with a friend so vigorously that he coded a program to compare yhe wins of betting randomly or on lagging possible outcomes of a randomly generated number. Betting on lagging outcomes brought more wins.

Can you elaborate more on what you mean? I think I misunderstand you somehow as it seems to me betting on lagging outcomes cannot outperform betting randomly in the long run or the outcome is not random (or there’s a coding / concept error).

>Professional sports is not quite random though.

Absolutely.

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Eric1969 t1_izt3tqu wrote

My friend’s theory was that lagging outcomes (ex: tails having come up 20 times for 40 heads) would result in these outcomes having a higher probability than the theoretical probability (50% for heads and tails) of showing up, as they would surely eventually catch up. I tought the probability remained 50% regardless.

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Mooks79 t1_izt3zcr wrote

I’m with you. I think if your friend’s code showed otherwise then there’s a flaw in the code and it’s not doing quite what it should be. Would they be willing to share it?

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Eric1969 t1_izt69qy wrote

It was 30 years ago in visual basic. So I don’t have access to it.

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Mooks79 t1_izt6qzt wrote

Ah! If I were you I would stick with your original thinking as I’m reasonably confident there was a coding issue or the set-up of the simulation wasn’t quite what it should be. If I have time I might try and knock something together myself, but that’s a big if as I’ve got a mental couple of weeks.

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Eric1969 t1_izt83c8 wrote

I agree. Also, the random numbers produced by a computer are “pseudo-random”.

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Mooks79 t1_izt8d0z wrote

They should be random enough, albeit improperly generated random numbers could be a cause. My money is on them setting up the simulation incorrectly, though. When I say incorrectly, I mean it could be that they haven’t set the simulation up quite as they think they have.

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Mooks79 t1_j1dtis7 wrote

Finally got round to knocking up a simulation, can confirm that the two methods (randomly choosing whether to bet H or T, or using the lagged counts) both give the same (0.5) win rate, as expected. Indeed, any strategy (e.g. always choosing H or T) will yield the same win rate for a truly random coin. I suspect there was a slight glitch in your friend’s simulation. Happy to share (R) code and plot(s) if you want.

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MarkVarga t1_izs4k1b wrote

I'm really glad you are doing these! Are you planning to check whether the most likely/medium option is a better strategy on the long run?

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ikashnitsky OP t1_izwfa4l wrote

Thanks, I can't see how the medium option may be beneficial, I guess this would be betting on the draw most of the times. I can check, of course.The question is: how do I report back the results? I feel I have already exhausted the limit of attention people are willing to spare here =)

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Grenadefisherman t1_izspavr wrote

I really like the idea of what you have been doing but the presentation of the date hurts my eyes. Too many lines!!

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Lochbriar t1_izsdxiq wrote

"What happened in 2019/20?"

There might have been something or other that had an effect on one or two things.

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jaytee158 t1_izsq8ih wrote

Yeah, Covid destroyed home advantage and the bookies couldn't adjust quickly enough.

I know you know this but pointing out for others

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ThankGodSecondChance t1_izsxrep wrote

Disagree. At the halfway point, long before covid really was hitting, the damage was already done. That year pretty much stayed level after January

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Lochbriar t1_izt4hea wrote

Yeah I was being snarky, the math suggests that COVID stopped games at the 300 mark. It's effect would be limited to the final spike.

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jjwoodworking t1_izsrkg3 wrote

What is the curve of end of season winnings. Is it a bell curve centered at 0? Looks like it might be

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