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Show HN: Have fun betting virtual (not real) money on predictions from HN users
I wanted to see how difficult it would be to build a web app using a sub-$300 android smartphone. Decided to build a fun predictions website where you could bet virtual (not real) money on predictions made by others, and also make predictions of your own.
Building it turned out to be considerably easier and more fun than I anticipated.
Primary tools used were:
# QuickEdit as the mobile code editor (Note: the free version of the QuickEdit app is riddled with ads, it shows an advert each time you close a tab, but it unfortunately had the best UI of the 3 or so Android code editors I tested. Ended up using NetGuard to block it from retrieving & displaying ads),
# PHP for the Backend ( custom PHP microframework I've used and built on over the past few years ).
# jQuery for the frontend js (cringing) - it appears I'm simply too lazy to learn React/Vue/et al. Every once in a while, I pick one of them to learn, but I always end up returning to jQuery - or time-permitting - amateur level vanilla JS.
# Bootstrap for the CSS - Battle-tested. For a purely backend dev with minimal design skills, good ol' Bootstrap (and in a growing number of cases, Tailwind) is always a life saver.
# Whole thing is hosted on 2 VMs (1 hosting the web app, and 1 hosting Redis & MySQL).
# As to the site itself, it turned out to be pretty cool to play around with. Go there, view the predictions, bet on the predictions you believe will come true, or against the ones you think will not. You get $50,000 to bet with (not real money). No signup is required to bet, but a quick signup is required to make a prediction. Hope you guys like it, and please be ruthless in telling me of any bugs you've found.
So go on here => kudotap.com
And Have Fun!
- oumua_don17 4y agoI predict that your site will be renamed as HNLadsBroke in 2023!!!
- exabrial 4y agoThere is _literally_ nothing wrong with your javascript on the page, FYI. stick with your toolset.
- algo_trader 4y agoSure, for an mvp. Quick and clean output But what happens as you start adding stuff. Toaster notification, user badges, swipe actions. I an not a JS expert, but it seems a modern library will have these built in ? EDIT: would be interesting to hear the original poster's opinion
- kqr 4y agoNot original poster, but I also sort of don't understand the question. You do what you would do to evolve any MVP: swap out one part at a time to something that scales better. It's just a frontend.
- jsty 4y ago> But what happens as you start adding stuff. Toaster notification Sounds like an amusing corollary to Zawinski's law. "Every program attempts to expand until it can notify you your toast is done..."
- exabrial 4y agoNpm would be a 1000x increase in codebase size… for notifications.
- habibur 4y agoOrder by most active bets at the top. Right now the page starts with dead claims and you find pretty active and good ones while scrolling down.
- pbhjpbhj 4y agoIt's this just mining HN hive mind for "insider" information?
- giansegato 4y agoeven if it was, everyone would benefit from the information (it being public)
- quickthrower2 4y agoThe insider information being the wisdom of the crowd. "Outsider information" would be a better description.
- hathym 4y agoIt would be more fun if you can bet your real HN points :)
- demarq 4y agoThis is a banger!! I already know I’m going to like it
- dvh 4y agoIt doesn't allow making prediction to 2030 so I just leave it here: I predict that by 2030 none of the top 10 US car manufacturer will offer self driving in their cars (except for simple autobreaking). Even those manufacturers that offer some self driving now will stop offering it by 2030.
- szemy2 4y agoI'm interested in the argument for this!
- dvh 4y agoWhen your neighbor Joe in his 1987 Buick run over your cat, you know he has 2 mortgages on his house and wife with cancer. When a self driving car runs over your cat or ding your fence post, you will gladly sue the multi billion dollar company, just for the settlement money. It will unleash the neverending stream of lawsuits and companies will be forced to stop offering self driving or go bankrupt. Yeah, they can afford best lawyers, but not 500 new lawsuits every day.
- leononame 4y agoWouldn't car companies just lobby for some law changes that would make the "drivers" responsible rather than the manufacturers? Or alternatively, allow self driving only on highways and such, where it's much safer? I don't think progress is stopped that easily
- szemy2 4y agoThere was a case with Ford in the 70s were they calculated that a retribution cost per person would be around 200k - calculated the likely effect of the cars busting into flames because they had an design flaw. They realised they are still better off than to recall all vehicles. As the story illustrates, there might be situations were expecteded litigation is worth it. I'm not saying this is morally right, but companies will try to maximize their profit anyway, even if there are (calculable) risks involved. In the case of self-driving this might mean being a profitable car manufacturer vs becoming a niche, enthusiast car producer for people who still enjoy driving as a leisure. Here is one of essay on this: https://studymoose.com/a-utilitarian-argument-in-the-ford-pinto-case-essay https://studymoose.com/a-utilitarian-argument-in-the-ford-pi...
- IIAOPSW 4y agoI predict this platform of yours will still be up and running in a year from now.
- sc90 4y agoConsider letting users add an explanation for each prediction so that we know the reasoning behind it.
- euphetar 4y agoNo way to assign probabilities? I prefer metaculus
- sshine 4y agoBehavioural economists as well as poker players know that people make very different decisions when the money is real. The psychology is different.
- Tenoke 4y agoWhile generally true, for what is worth the recently popular play money prediction site Manifold Markets, as well as the general predictions site Metaculus both seem to do well and reflect what you see elsewhere quick.
- phailhaus 4y agoIf you "charge" people by requiring them to spend time doing something in order to reset their supply, then that's sufficient to give the money some value.
- leobg 4y agoKant knew this, too: > The usual touchstone, whether that which someone asserts is merely his persuasion — or at least his subjective conviction, that is, his firm belief — is betting. It often happens that someone propounds his views with such positive and uncompromising assurance that he seems to have entirely set aside all thought of possible error. A bet disconcerts him. Sometimes it turns out that he has a conviction which can be estimated at a value of one ducat, but not of ten. For he is very willing to venture one ducat, but when it is a question of ten he becomes aware, as he had not previously been, that it may very well be that he is in error. If, in a given case, we represent ourselves as staking the happiness of our whole life, the triumphant tone of our judgment is greatly abated; we become extremely diffident, and discover for the first time that our belief does not reach so far. Thus pragmatic belief always exists in some specific degree, which, according to differences in the interests at stake, may be large or may be small.
- cookie_monsta 4y agoGeez, people in the olden days took a long time to say simple things like "put your money where your mouth is"
- 4y ago
- algo_trader 4y agoInteresting. Why a 300$ phone? Can u share how long it took to build and what is your day job ?
- rose_ann_ 4y agoTook roughly 2 weeks from start to finish. Work as a web dev in an accounting firm. As to the choice of the phone, got a Samsung Galaxy A23 on takealot.com a while back and decided to use it to build a site
- quadrature 4y agoNow you have a second job updating the prediction outcomes :P. I was thinking it would be cool to sync them from github so folks could contribute an outcome.
- rose_ann_ 4y agoLol, a second job? I sincerely hope not. I don't think the site'll garner much interest though. Betting virtual money doesn't really seem like a mainstream activity. Just wanted to put it out in the wild and get critiques.
- NavinF 4y ago> Betting virtual money doesn't really seem like a mainstream activity. You'd be surprised: https://www.metaculus.com/ https://www.metaculus.com/
- olalonde 4y agoDid you type the code on the phone's touch screen or using an external keyboard?
- rose_ann_ 4y agoI used the phone's touchscreen
- mwint 4y agoOh how I wish this existed a couple years ago, when everyone was making various shades of "the world is going to end" predictions. I would be a virtual billionaire!
- deleted 4y ago[deleted]
- netsharc 4y agoThere were real life betting markets for all events, and people were even using it to predict the state of the world based on "wisdom of the crowd". But IIRC they mostly got outlawed, so they just exist for closed circles now.
- madrox 4y agoI actually built this as a startup two years ago. There's quite a few "prediction market" website out there which can be both for karma and real money. We tried to combine predictions with social media to allow users to build authority. The hard scale problem here is the reputation of the artibers of the challenge. We ended up pivoting when we realized to make this compelling at scale we'd essentially become a news site, and we didn't want to do that.
- armchairhacker 4y agoWhat if someone posts a very likely or unlikely bet (e.g. "the next Mega Millions numbers will be ..."? Can everyone bet $30,000 against and then everyone gets $30,000? You may want a system where, the more skewed a bet is, the less money gets paid out by the majority side and more money gets paid to the minority. That way, bets like those don't really get you anything, unless you bet the unlikely case and win, then you get a well-deserved jackpot.
- kqr 4y agoA quick way out of this issue is to ask users not for how much to stake, but how confidently they believe something to be true, and then reward/penalise based on a score function derived from this and the actual outcome.
- rose_ann_ 4y agoThat's a pretty good point, though in this case the 'winnings' are simply a fixed multiple of the virtual amounts bet.
- tlyleung 4y agoA parimutuel system would solve this. When settling the bet, the pool of money is divided among those that backed the winning combination, in the ratio they contributed. You can also display the odds based on how much money is behind each combination.
- kqr 4y agoOne characteristic of a parimutuel system for a relatively illiquid market is that the odds can swing quite drastically whenever anyone bets. In fact, even the amount one person bets is going to affect the odds they will get, so you need to display a table of odds for various bet sizes. This may or may not be a problem, but I've found it requires more... infrastructure (notifications etc) for people to avoid being confused by it, and give people a chance to withdraw their bet if the odds are no longer favourable (alternatively put in stops, but that also complicates the system.)
- quickthrower2 4y ago
- TheCowboy 4y agoOne ever underrated challenge with prediction markets is creating clear and concise rules for interesting questions, while the easy part is the tech powering the exchange. For example, "James McIntyre is predicting that: There will be a global stock market crash in 2024." What constitutes a crash here? Or "Patricia Davenport is predicting that: An absolutely massive natural gas discovery will be made by a Southern African country before the end of 2023." has no clear meaning.
- bogota 4y agoIf you can’t measure it based on some agreed upon data source you can’t bet on it. Well you can but just have fun getting your money
- soared 4y agoProbably impactful for real money websites, but I can’t imagine anyone really cares for this fun money website where a good judgement can be applied pretty easily.
- gpm 4y agoIt's obviously more impactful for real money websites, but realizing that two people mean different things by the same statement is pretty common. I think even fake money prediction markets are much more interesting if you largely avoid that.
- TheCowboy 4y agoI've played plenty of both and it really is just as annoying with play money if the rules of the game are flawed. It just feels like cheating if a loose interpretation of the rules let's people off the hook for a bad prediction.
- Waterluvian 4y agoDidn’t this issue loosely arise with the 2020 US election and all the people trying to argue that the authority on who won was not legitimate? Most bets cannot be discretely quantified because there’s always something to argue about (such as the measurement methods). I think all it requires is for all parties to agree on an authority that makes the call.
- aliljet 4y agoI can't not make this joke: Where do I send my BTC?
- jtvjan 4y agoMy preferred way of editing text on Android is to run Vim in Termux. If there's a terminal editor that you like (nano, emacs, joe, ed are all available too), try running it through there.
- aoeusnth1 4y agoIs there a good reason to use this over Manifold (http://manifold.markets http://manifold.markets)?
- glotchimo 4y agoSeems like Manifold requires a Google account which is definitely a mark against it for many
- c0balt 4y agoThe difference afaict is that Manifold both requires a google account and is effectively just using cents as an abstraction over USD. In comparison the bets in the submission are "truly" based on virtual, nin-exhangable money. Additionally, the submission is focused on HN in comparison to general bets like Manifold.
- remram 4y agoYou can't get the money out, it all goes to charity. So while you're not betting free money, you are not betting your money either, it is consumed before you bet either way.
- echelon 4y agoThis is awesome! Kudos (no pun)! I'd really like to wager real money. Due to gambling laws, I'd be fine if this went to charity, in a similar vein to longbets. It's more about vision and narrative than winning money, anyway. Building esteem for sometimes contrarian viewpoints. (If you can predict where the world is moving, you can make money on that regardless.) An internet track record would be amazing.
- rose_ann_ 4y agoThank you! As I said in previous comments I really just made the site as an intellectual exercise.
- belkarx 4y agoThere are other prediction markets that use real money (I believe predictit [0] is one of them) [0] https://www.predictit.org/support/what-is-predictit https://www.predictit.org/support/what-is-predictit
- alwillis 4y agoCan't count the number of times I've wanted something like this for Hacker News! There have been quite a few hot takes (especially about Apple) where I would have bet against that person's prediction happening. Glad it's an option now.
- codetrotter 4y ago> Please fill out the 'Last Name' field (ensure it contains a least 2 characters (and does not contain any unusual special character)). Please allow a wide range of Unicode characters. I am not able to sign up, because the site does not allow me to type my last name, it seems. The letter “ø” is not an unusual special character..
- aliqot 4y agoWhat is that, some kinda crazy-8 or what?
- TaylorAlexander 4y ago“Ø is a letter used in the Danish, Norwegian, Faroese, and Southern Sámi languages. It is mostly used as a representation of mid front rounded vowels.” https://en.wikipedia.org/wiki/%C3%98 https://en.wikipedia.org/wiki/%C3%98
- deleted 4y ago[deleted]
- michaelnoguera 4y agoFriendly reminder that if op decides to allow more special characters in the name fields, they should check it does not open a stored XSS vulnerability. (Names are displayed to all site viewers on the predictions page.)
- shakna 4y agoAlso, just because it's a pet peeve - Last and/or Family names are not universal. Plenty of people with only one name.
- laserbeam 4y agoNormally, that's a good idea. But based on OP's description this is a prototype or exersice in building /delivering an mvp. I don't feel that full unicode support is usually part of an mvp.
- kaputmi 4y agoWithout odds/probabilities this is much less interesting!
- vagab0nd 4y agoInteresting site. How do you decide on the result of a bet? Where do you get the truth? What if the bet is described ambiguously? Or worse yet, something like "This prediction will be false".
- quickthrower2 4y agoI think the "market creator decides" works really well for play money markets. https://manifold.markets https://manifold.markets doe this. The risk of a "rug pull" is often discussed when assigning probabilities, and you can see people's history to decide if you trust them. A good market will have a well thought out process of deciding the truth. For stuff where there is a betting market or money market, it is easy to refer to that. Otherwise for something like "Will Russia invade Ukraine", at the time the definition of "have they invaded yet" had to be figured out, especially as no one knew how far it would go.
- kqr 4y agoPicking your brain for a slightly related question: how would you propose setting the initial odds, assuming the market creator can also bet?
- quickthrower2 4y agoBig question! (And sorry I might have been confusing. I am not the OP or creator of the Show HN, but I jumped in and answered how I would do it) First decide if you want the bets to be taken by an algorithmic market maker (so anyone who wants to place a bet can place it, but they get slippage, like Uniswap) or an order book (more like you say "Ill bet $500 at 33%" an then someone else says "I'll take the other side", like Betfair) Let's assume you use a AMM. Then the way to do it is let the market maker pick the probability, and provide the initial liquidity to the AMM at those odds. So they are incentivized to get it right. To derisk them a bit (after all they are taking bets with the least information, right at market open) you give them commission or something like that on bets placed. These are complex decisions. Manifold.markets went though various iterations. They are erring on the side of simplicity for new users, so they fix the odds. You don't get a choice, it is 50%. Because it is an AMM you quickly revert to the right probability. Of course, since you time the creation of the market you could make those correcting bets yourself just in time.
- texaslonghorn5 4y agoif I click "View the Latest Predictions & Bets on Kudotap" on the homepage and then go back to the homepage, the button is unclickable the second time