Patrick Lung
Patrick Lung

Lottery funding mechanism

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This is live now at pevl.xyz! Please read this 1-pager on a 0-fee lottery first if you haven’t already!

Principles

Most important is maximizing the initial prize pool $ amount and # of entrants to make a big splash, then maintaining most of that size in subsequent raffles. This is because users are drawn to large lotteries, and previous attempts failed because raffle amounts were too small.

High-level, this means:

  • Have only one main game, rather than more selection
  • Allocate significant points for users/activity the first few hours/days of launch
  • Funds in lottery prize pools should stay unless withdrawn

Lottery Implementation

The best approach we’ve identified is by having jackpots that are continually funded initially by LPs.

Goal:

  1. Offer a low variance way to farm Blast airdrop for LPs
  2. Offer a high-variance, positive EV way to play the lottery for retail
  3. Incentivize growing jackpot size
  4. If the jackpot is won, next jackpot pool is restarted with a large pool size
  5. Limited gas and complexity for jackpot drawing

Mechanics

  • Users benefit since they have a positive EV option to win a very big jackpot (high variance) by buying raffle entries. The lottery itself is neutral EV, but since they get a small share of the Blast developer airdrop, it’s positive EV.
  • LPs benefit since they have a way to get significant access to the Blast developer airdrop by providing their funds at a positive EV, though with low variance. They contribute a large sum (principal), then choose a % to risk as a jackpot (stake), and get the vast majority of the Blast developer airdrop that we share.
  • The prize pool is initialized daily with LP’s stake. Jackpot drawing is per day. Only one winner can win each jackpot. Any ticket proceeds beyond the initial pool size is added to the jackpot.
  • If ticket proceeds ≥ initial prize pool, a jackpot must be won. If ticket proceeds < initial prize pool, jackpot may not be won.
  • If jackpot is won, user takes home prize amount. Money from entries up to the initial prize pool size is added to LPs’ principal, and then they contribute another % of their principal.
  • If jackpot is not won, money from entries is shared to LPs such that
    • Preferred approach - rest of doc/examples use this approach: Their principal and stake remain at their target risk allocation %.
    • Alternate if easier to build - not covered in doc: The proceeds only increase their principal

Prize pool details

  • LPs choose the level of risk they’re willing to take, with minimum of 1% and max of 100%
    • Recommended range is 5-20%.
    • We have a minimum because we don’t benefit if they deposit into our contract and do nothing. The maximum is at 100% since retail may want to farm airdrop too, and want lower variance than the lottery itself.
    • Eg. Deposit $1000, select 10%. $100 is at risk at a time for lottery pool.
  • Users can buy lottery tickets to win the jackpot. It is neutral EV since they get a % of lottery tickets depending on size of jackpot. Users cannot get refunds on tickets.
  • Prize pool grows slightly when no jackpot is drawn, and decreases slightly when jackpots are drawn.
  • LPs can submit a change to their stake %, add or remove their principal or stake %, prior to a lottery commencing. All state changes take place between when the lottery draws and the next lottery commences.

Points:

  • Our points program rewards users for deposit liquidity into our contract, generating native yield, as well as building large jackpots.
  • At the end of a season, these points claim 80% of native yield and 51% of our Blast developer airdrop.
  • Users earn points immediately when they buy lottery tickets. By granting these immediately, they are able to go play mini-games instead of waiting daily. Users come to use primarily to win the lottery, so they get minimal points for buying tickets.
  • LPs deposit money and commit a small fraction to serve as a guaranteed jackpot. Since jackpot size is most important to attract users to buy tickets, LPs get significant points for the amount as risk (stake), with minimal points for the amount that is not at risk (principal).
  • Points are calculated by multiplying $ amount deposited into contract * time * multiplier
    • $
      • 1 point is awarded for every 0.001 ETH that’s locked in our contract for 1 day
    • Time
      • At risk for jackpot only starts counting when money is actively at risk.
      • Principal and user ticket entries start counting immediately. Eg. If you deposit 1 ETH principal at noon and lotteries run at midnight, you get 500 points for the remainder of the day.
    • Multiplier
      • At risk for jackpot is 10x multiplier
      • In the principal is 1x multiplier
      • User entry is 1x
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Examples

Lottery walkthrough

  • Let’s assume there are three LPs.
    • LP A deposits $10000, selects 10% risk. $1000 is at stake for lottery jackpot. Gets 9000 points for $9000 in principal, 10000 points for stake.
    • LP B deposits $20000, selects 20% risk. $4000 is at stake for lottery jackpot. Gets 16000 points for principal, 40000 points for stake.
    • LP C deposits $250000, selects 2% risk. $5000 is at stake for lottery jackpot. Gets 245000 points for principal, 500000 points for stake.
  • Lottery #1 prize pool is $10,000.
  • $5000 worth of entries were bought by 5000 users, each putting $1 in
  • If lottery is won (50% likelihood, based on $5k entries / $10k prize pool)
    • 1 user takes home $10000. 4999 users get $0. Thus, this is high variance for lottery participants.
    • All LPs lose their stake. This is 2-20% of their stake, so this is low variance for LPs.
    • They get a % of ticket proceeds based on their % pool ownership.
      • LP A had 10% ($1000) of the pool, so gets $500 added to principal.
      • LP B had 20% ($4000) of the pool, so gets $2000 added to principal.
      • LP C had 50% ($5000) of the pool, so gets $2500 added to principal.
    • LPs contribute again to starting up the lottery pool.
      • LP A has $9500 principal, 10% is $950.
      • LP B has $18000 principal, 20% is $3600.
      • LP C has $247500 principal, 5% is $4950.
    • New lottery pool is now $9500.
  • If lottery is not won (50% likelihood)
    • LPs earn a % of the entries based on their LP contribution part of the pool ownership. LPs get the following added to their principal and stake such that their target % allocation remains the same:
      • A had 10% of the prize pool, so gets $500, and had 10% risk, so 10% of that $500 ($50) gets added to the stake, while 90% ($450) goes to the principal. Now, there is $9450 principal and $1050 staked.
      • B had 40% and gets $2000, and ends up with $17600 principal and $4400 staked.
      • C had 50% and gets $2500, and ends up with $247450 principal and $5050 staked.
    • Next lottery has a $10500 prize pool.
    • Assume next lottery has $5000 in entries and is not won.
      • After lottery #2: LP A now has $9900 principal, B has $19276 principal, and C has $249807 principal.
    • Next lottery has a $11017 prize pool.

Model of LP’s principal and stake here. Change different risk % and jackpot results here:

Oversubscribed lottery pool timeline

  • LPs have $100000, and set risk at 10%
  • Initial prize pool is $10000
  • 5000 users buy $1 ticket each, so entries = $5000 → Prize pool is still at $10000
  • 5000 more users buy $1 tickets each, so entries = $10000 → Prize pool is still at $10000
  • 1 addition user buys $1 ticket, so entries = $10001 → Prize pool is now at $10001
  • 9999 more users buy $1 ticket, so entries = $20000 → Prize pool is now at $20000
  • Currently money involved:
    • $10000 from LPs for initial prize pool
    • $20000 from entries
  • Jackpot will be won because ≥ 100% of initial prize pool was sold
    • 1 user takes home $20000
    • LPs get $10000 back, but they had put up a $10000 stake, so they break even.
    • Now LPs put again $10000 back because they still have $100000, and risk is still at 10%

This case is accounted for, try changing entries > prize pool:

Unsubscribed lottery pool timeline

  • No LPs
  • Initial prize pool is $0
  • All ticket entries go into jackpot

LPs unstaking timeline

  • LP has $100000, set 10% risk
  • At midnight, lottery begins and initial prize pool is set to $10000
  • If LP wants to withdraw all their money, they can only do so at the end of lottery #1
  • LP submits request in advance, to withdraw money or change stake % before lottery #2 begins
  • At the end of lottery #1, their principal and stake are withdrawn such that it does not enter lottery #2
  • If $1 entries were bought:
    • Jackpot is won, then LP loses entire $10000 stake, and gets $1 back

Points rewarding timeline

  • Lottery at midnight end, and start.
  • Today is Jan 1.
    • LP#1, #3, #5 deposits 10 ETH principal at Jan 1 noon, and sets 10% at risk.
      • They get 5000 points right away (10 ETH principal * 1000 points/ETH * 12h remaining / 24 hour left in day
    • Retail buys 10 ETH of tickets at Jan 1 noon
      • They get 5000 points too (10 ETH * 1000 tickets/ETH * 1 point/ticket * 12h remaining / 24 hour left in day)
    • LP#2 deposits 10 ETH principal at Jan 1 11pm, and sets 10% at risk.
      • They get 416.67 points right away (10 ETH principal * 1000 points/ETH * 1h remaining / 24 hour left in day)
    • LP #5 asks to withdraws all.
      • Cannot withdraw immediately. You must wait until end of the lottery. Thus, their 10 ETH generated native yield for 12 hours.
  • Lottery #2 start Jan 2 12:01am
    • LP #5 now has 10 ETH principal, 0 at stake. Claims their ETH.
      • LP #5 create new position at 12:01am, deposit 10 ETH, get 10000 points
      • If this is a problem, we can add a clause: If you withdraw <24h, we deduct your points.
    • LP #1 and LP #2 both get the same 19000 points per day
      • (10 ETH * 10% stake * 1000pt/ETH * 10x multiplier for stake = 10000pts for stake;
      • (10 ETH * 90% not at stake * 1000 pt/ETH * 1x multiplier for principal) = 9000pts for principal
    • LP #1 edit position - don’t add ETH, but changes stake to 20%
    • LP #2 withdraw all
    • LP #3 edit position - add 10 ETH at Jan 2 noon, and changes stake to 20%
      • LP #3 gets immediately 5000 points right away (10 ETH principal * 1000 points/ETH * 12h remaining / 24 hour left in day
    • LP #4 is brand new, and adds 10 ETH at Jan 2 noon and sets stake at 50%
      • LP #4 gets immediately 5000 points right away (10 ETH principal * 1000 points/ETH * 12h remaining / 24 hour left in day
    • No one enters the lottery, so stake and principal remain the same.
  • Lottery #3
    • LP #1 position is 8 ETH principal, 2 ETH stake now. They earn 28000 points per day
      • (10 * 0.2 * 1000 * 10) + (10 * 0.8 * 1000)
    • LP #2 position is 10 ETH principal, 0 ETH stake, 0% stake. They earn 0 points per day.
    • LP #3 edit position
  • At end of day, they get 5000 points, since none of their money is at risk yet.
  • Next day, the lottery runs.
    • LP gets 9000 points for the principal, and 10000 points for the $1000 at risk for the jackpot, or 19000 points
    • A user who buys 0.1 ETH of tickets exactly at midnight when the lottery beings gets 100 points.
    • A user who buys 0.1 ETH of tickets at noon gets 50 points.

Technically speaking, we issue points at two possible times:

  1. Immediately whenever you add ETH, we give you points based on time remaining until end of lottery → is the same as a retail user buying a ticket
  2. Daily, when a lottery is about to begin, we give you points based on your principal and stake.

GTM

Launch points multipliers

To incentivize early adopters to provide liquidity and buy lottery tickets, we are providing additional incentives for the first month.

This is the points calculation for LP’s at risk stakes:

Raffle #
Launch bonus multiplier
Multiplier for money at risk (staked)
Total points per 0.001 ETH per day
Daily Raffle 1
5x
10x
50
Daily Raffle 2
4x
10x
40
Daily Raffle 3-7
3x
10x
30
Daily Raffle 8-14
2x
10x
20
Daily Raffle 15-30
1.5x
10x
15

This is the points calculation for raffle tickets bought and LP’s principal:

Raffle #
Points multiplier
Multiplier for tickets bought or LP principal
Total points per 0.001 ETH per day
Daily Raffle 1
5x
1x
10
Daily Raffle 2
4x
1x
8
Daily Raffle 3 - 7
3x
1x
6
Daily Raffle 8-14
2x
1x
4
Daily Raffle 15-30
1.5x
1x
3

Long-term

This approach works in the short and medium term to attract liquidity providers, since we expect Blast to continue their developer airdrop for 1+ years. Blur continues to offer airdrops today, over a year post-launch.

In the long-term though, if the developer airdrop is reduced or the mechanics change, LPs may move their liquidity somewhere else that offers higher yields. My thinking on this is:

  1. Would be great to have this problem - we have a product that retail and LPs use, and the reducing airdrop is what affects us
  2. We could provide liquidity ourselves - from the airdrop we get, we can be our own LPs to ensure there’s always something in the pool
  3. There are many ways to monetize, and provide these earnings as yield - the frontend (website/telegram bot) can charge fiat onramp fees or swap fees, and this can be returned to points holders/LPs to supplement yield and provide reason to keep liquidity here

Ultimately, I see this Blast airdrop farming phase as the GTM to attract liquidity, such that we can build a consumer product where crypto is under the hood.

If we can succeed with Blast users and LPs, I’m confident we’ll be able to make it work beyond.