WARNING: This is not-even-beta software. USE AT YOUR OWN RISK and make sure you know what you are doing.
3/26 5PM PST: Oracle bracket updated after elite 8. High score is 40, second place is 36, rest of the field is eliminated.
3/19 10PM PST: Oracle bracket updated after the round of 32. High score is 36, second place is 34, rest of the field is eliminated. Max possible score at this point is 48.
3/13 2PM PST: Seems like a few people are having trouble running python. For those of you who are less tech-savvy, please fill out a bracket, take a screenshot, and share on the reddit post. I will reply with a string for you to use in your transaction (you can use MEW).
3/12 9AM PST: Contract deployed! Submit a bracket before 11:00 AM EST on Thursday, March 16!
Welcome to March, my favorite month! I love this month because here in America we host the best sports tournament on the planet - the NCAA Basketball Tournament (a.k.a. March Madness).
64 college basketball teams from all across America go head-to-head in a single-elimination fight to the top. Well, technically there are 68 teams, but I'll get into that later.
The week before the tournament starts, it is customary here in America to fill out brackets with your predictions of who will win each game. It's a lot of picks (59 games) and the probability of guessing every game correctly is 1 in 2.4 trillion. Within a bracket pool (usually comprised of your friends and family), the person who picks the most winners is crowned the champion. There are many strategies ranging from picking your favorite teams to always picking the highest seed (usually a bad idea in big pools) to consulting a probability distribution. Which is the best strategy? Who knows.
As a huge Arizona basketball fan I thought it would be fun to put my Ethereum skills to the test and deploy a bracket pool to the Ethereum network.
If you would like to participate (buy in is 0.5ETH), read on!
Since I have a real job at ConsenSys and I just recently though of this, I don't have time to put out a fully functioning website, so I'm going to force you to use Python.
The tournament starts promptly at 11:00 AM EST on Thursday, March 16 (unix = 1489680000) and concludes with the championship game at 9:00 PM EST on Monday, April 3 (ending roughly 3 hours later, at unix = 1491541200).
You will fill out a bracket and submit this to the blockchain along with the buy-in cost of 0.5 ETH. You must submit your bracket before the tournament commences (i.e. before 1489680000). You may only submit one bracket per Ethereum address.
Points are allocated as follows:
- 1 point for submitting a braket
- 1 point for each correctly chosen team in round of 64, 32, sweet 16, and elite 8
- 2 points for each correctly chosen team in the final four
- 4 points for the correctly chosen champion
This means the highest possible score is 69.
NOTE: Each game is scored independently of others, so as long as you pick the winning team, it doesn't matter if you incorrectly picked their opponent.
I will be responsible for submitting the oracle bracket (that is, the winners of the each game). I will add to it each day once games are concluded and you may compare your score whenever you'd like (more on this later).
Shortly after the tournament ends (give me ~15 min to update the oracle), you will have 72 hours to submit your score for review (ending at 1491541200). When you submit your score (discussed later), you will be added as the leader if your score is higher than the current leader score. The highest score wins. If there is a tie, the pool is distributed evenly across winners.
And before you ask, yes I know that you need to trust me to be an arbiter of the truth. If you're uncomfortable with that, you are welcome to re-deploy this contract and start your own pool.
I have built an escape hatch so if something goes wrong, I will notify everyone with instructions on how to withdraw your 0.5 ETH. (I've actually already used this after I deployed a borked contract earlier) Sorry in advance if that happens.
There are no fees. 100% of the pool goes to the winner[s].
Before doing anything, you will need this repo. Open up your command line, navigate to a new directory, and type the following:
git clone https://github.com/alex-miller-0/ethereum-march-madness.git
It's probably a good idea to fill out a bracket visually first. You can find one here or here. You will only need this for reference later.
I guess I should address the issue of there being 68 teams. For some reason, the NCAA tournament has the 4 weakest teams each play an extra game ahead of the tournament to vie for a 16 seed (the worst seed). Also, 4 "bubble" teams play for the 11 seed. Anyway, it's not important. What I'm going to do is let you pick either one of the extra teams to advance (basically treat them as a package). It will make more sense when you fill out the bracket.
To boot up the tool:
python cli.py
If you run into problems, make sure you have python installed along with the following packages: pysha3, glob, pickle (the latter 2 should come with your python installation). To install a python package, make sure you have pip installed and run pip install <packagename> (you may need to include sudo at the front if that doesn't work).
Once the program in running, it will ask you for your picks for all 59 games. If at any time you want to reset your bracket, close out of the program (control+C) and restart. If it asks you to use an old bracket, say no.
After you're done with your bracket, you will see something like the following:
Cool. You've made your picks. Now we need to put it on the blockchain.
Setup your bracket:
--------------------
Please copy the following string and send a raw transaction with it as the data parameter:
### YOU MUST SEND 0.5ETH WITH THIS TRANSACTION ###
0x58b72327000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000005000000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000000700000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000500000000000000000000000000000000000000000000000000000000000000030000000000000000000000000000000000000000000000000000000000000007000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000050000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000b000000000000000000000000000000000000000000000000000000000000000e0000000000000000000000000000000000000000000000000000000000000007000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000005000000000000000000000000000000000000000000000000000000000000000b0000000000000000000000000000000000000000000000000000000000000007000000000000000000000000000000000000000000000000000000000000000500000000000000000000000000000000000000000000000000000000000000070000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000050000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000030000000000000000000000000000000000000000000000000000000000000007000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000005000000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000070000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000700000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000500000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000300000000000000000000000000000000000000000000000000000000000000070000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000050000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000700000000000000000000000000000000000000000000000000000000000000050000000000000000000000000000000000000000000000000000000000000007000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000000700000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000001
That hex string at the bottom is what you will need to copy and paste into your Ethereum wallet in the data field.
If you're using My Ether Wallet:
- Go to
Send Ether & Tokens - Set the
To Addressfield to0xae251c170b388fbbfb5a16f925b0ace951820200 - In the
Amount to sendfield, put0.5ETH. - In the
gasLimitput2000000(it shouldn't use this much and the remainder will be refunded). - Click
Advanced: Add Dataand paste the hex string from before into theDatafield. - Sign and send the transaction!
If you have a node running locally, you can do cURL requests:
curl --data '{"method":"personal_unlockAccount","params":["<your address>","<your password>",null],"id":1,"jsonrpc":"2.0"}' -H "Content-Type: application/json" -X POST localhost:8545
curl --data '{"jsonrpc":"2.0","method":"eth_sendTransaction","params":[{"to":"0xae251c170b388fbbfb5a16f925b0ace951820200","gas":"0x1E8480","value":"0x6F05B59D3B20000","from": "<your address>","data":"<string you got>"}],"id":1}' -H "Content-Type: application/json" -X POST localhost:8545
You have now created your bracket!
Once the tournament starts, you can check your score by opening up a web3 console and doing the following:
var addr = "0xae251c170b388fbbfb5a16f925b0ace951820200";
var abi = [{"constant":true,"inputs":[],"name":"pool","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"abort","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"user","type":"address"},{"name":"region","type":"uint8"}],"name":"getQuarter","outputs":[{"name":"","type":"uint8[15]"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"withdraw","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"south","type":"uint8[15]"},{"name":"west","type":"uint8[15]"},{"name":"east","type":"uint8[15]"},{"name":"midwest","type":"uint8[15]"},{"name":"finalFour","type":"uint8[4]"},{"name":"championship","type":"uint8[2]"}],"name":"setBracket","outputs":[{"name":"","type":"bool"}],"payable":true,"type":"function"},{"constant":false,"inputs":[],"name":"issueWinner","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"leadingScore","outputs":[{"name":"","type":"uint8"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"region","type":"uint8"}],"name":"getOracleQuarter","outputs":[{"name":"","type":"uint8[15]"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"user","type":"address"}],"name":"getFinals","outputs":[{"name":"","type":"uint8[6]"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"leaders","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"user","type":"address"}],"name":"getCurrentScore","outputs":[{"name":"","type":"uint8"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"ABORTED","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"scoreBracket","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"getOracleFinals","outputs":[{"name":"","type":"uint8[6]"}],"payable":false,"type":"function"},{"inputs":[],"payable":false,"type":"constructor"}]
var contract = web3.eth.contract(abi)
var instance = contract.at(addr)
// Check your score
instance.getCurrentScore(<your address>)
// Get the total pool (in wei)
instance.pool()
Once the championship ends, you have 72 hours to submit your score if you think it is high enough to win (note: you can't win if you don't submit!). You will need to submit a new transaction to claim it. Use the following as your data parameter:
0xdc26824f
(fun fact: this is the first 4 bytes of the keccak_256 hash of the function you are calling, which is scoreBracket())
Make sure you do this from the same address you used to make the bracket!
If you're using My Ether Wallet:
- Go to
Send Ether & Tokens. - In the
Amount to sendfield, put0. - In the
gasLimitput2000000(it shouldn't use this much and the remainder will be refunded). - Click
Advanced: Add Dataand use0xdc26824ffor theDataparameter. - Send the transaction!
If you have a node running locally:
curl --data '{"jsonrpc":"2.0","method":"eth_sendTransaction","params":[{"to":"0xae251c170b388fbbfb5a16f925b0ace951820200","gas":"0x1E8480","from": "<your address>","data":"0xdc26824f"}],"id":1}' -H "Content-Type: application/json" -X POST localhost:8545
While you wait for the 72 hour window to pass, you can check the top scores using a web3 console:
var addr = "0x2dcbe558103caa847d5580604272321284cc312a";
var contract = web3.eth.contract([{"constant":false,"inputs":[],"name":"setAbort","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"pool","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"abort","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"user","type":"address"}],"name":"getQuarterScore","outputs":[{"name":"","type":"uint8"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"south","type":"uint8[15]"},{"name":"west","type":"uint8[15]"},{"name":"east","type":"uint8[15]"},{"name":"midwest","type":"uint8[15]"},{"name":"finalFour","type":"uint8[4]"},{"name":"championship","type":"uint8[2]"}],"name":"setBracket","outputs":[{"name":"","type":"bool"}],"payable":true,"type":"function"},{"constant":false,"inputs":[],"name":"issueWinner","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"leadingScore","outputs":[{"name":"","type":"uint8"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"leaders","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"user","type":"address"}],"name":"getCurrentScore","outputs":[{"name":"","type":"uint8"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"ABORTED","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"scoreBracket","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"user","type":"address"}],"name":"getFinalScores","outputs":[{"name":"","type":"uint8"}],"payable":false,"type":"function"},{"inputs":[],"payable":false,"type":"constructor"}])
var instance = contract.at(addr)
// Get the leader(s) (hopefully this shows your address!)
instance.leaders()
// Check the highest score
instance.leadingScore()
After the 72 hour submission period, I will call the issueWinner() function, which will send all funds to the winner(s) of the bracket pool. I will subsequently announce the winner and the winnings on Reddit.
Good luck!