How do house bankroll pools let players stake the house side in crypto roulette?

A bankroll pool lets anyone deposit coins into the contract that pays roulette winnings, in exchange for a share of the house’s results. Lost stakes flow into the pool and paid wins flow out of it, so every share tracks the house’s cumulative result, and over enough spins, the 2.7 per cent edge of a crypto games roulette wheel accrues to the shareholders. The steps below follow one staker through a month in a 100,000 USDC pool with a one per cent maximum payout, which caps any single win at 1,000 USDC.

1. The staker sends 1,000 USDC to the pool’s deposit function. The share price is 1.0000, because the pool holds 100,000 USDC against 100,000 shares, so they receive 1,000 shares. The pool now holds 101,000 against 101,000 shares, and the price is unchanged, because a deposit adds coins and shares in the same ratio.
2. Over the first ten days, players wager 40,000 USDC. The edge alone would deliver 1,080 to the pool, but a straight-up hit for 900 on day six pulls the actual result down to 620. The pool holds 101,620 shares against 101,000 shares. The share price is 1.0061, and the stakeholder’s 1,000 shares are worth 1,006.
3. Over the next ten days, players wager 50,000 USDC, and even money bets run against them. The house nets 2,780. The pool holds 104,400. The share price is 1.0337, and the shares are worth 1,034.
4. On day 28, two straight-ups hit in the same evening, one for 800 and one for the 1,000 cap. Across the final ten days, players wager 30,000, and the house nets a loss of 1,300 after those hits are set against ordinary losses. The pool holds 103,100.
5. On day 30, the staker returns 1,000 shares to the withdrawal function. The share price is 103,100 divided by 101,000, or 1.0208, so they receive 1,020.80 USDC. The pool now holds 102,079.20 against 100,000 shares, and the price is again unchanged by the withdrawal.
6. The month’s total wagered was 120,000. The edge alone would have produced 3,240 for the house, a 3.2 per cent return on the pool. The actual result was 2,100, a 2.1 per cent return, and the staker’s 1,000 became 1,020.80. Had the two hits on day 28 not landed, the return would have been closer to the edge.
7. Two figures deserve a second look. The one per cent cap meant the day 28 hits cost the pool 1,800 at most, and without it, a single straight up on a large stake could have taken several times that. And the share price never moved on the deposit or the withdrawal, only on play, which is what makes it a clean record of the house’s result.
8. The staker is exposed throughout to four things: variance in the house result, which over a month can go either way and over a year settles towards the edge; the maximum payout setting, because a pool allowing five per cent per win swings five times as far per spin as one allowing one; contract risk, because stakers’ coins are the ones the contract holds; and the coin itself, since a pool in USDC holds its value while a pool in ether moves with ether on top of the house result.

Staking the house side is taking the 2.7 per cent one spin at a time, with the same variance the house has always lived with. The share price is the scorecard, and it is public on the contract at every moment.