How do mining pools split rewards?

Bitcoin mining has a variance problem. A single modern miner pointed at the network is like one person buying lottery tickets against the entire planet: the expected value is real, but you might wait decades to see a single win. Mining pools exist to fix that. Thousands of miners combine their hashrate, find blocks regularly, and split the rewards.

Short answer: pools track each miner's contributed work as "shares," and when the pool finds a block, it divides the reward — currently 3.125 BTC plus transaction fees — according to a payout scheme. The scheme determines how much variance you absorb and how much the pool charges you for absorbing it. Pick the scheme, and you have picked your deal.

Why pools exist at all

Mining is a guessing game. Every miner races to find a hash below the network target, and the winner gets the block reward. Your chance of winning any given block is your hashrate divided by the network's total hashrate. With the network running near 800 exahashes per second, a single 100 terahash machine has an expected wait of roughly 22 years per block.

Twenty-two years, on average, for one payout. Most people cannot run a business on that.

A pool combines the hashrate of thousands of machines, so the pool finds blocks every day or every hour. The variance that would have crushed a solo miner gets spread across everyone. In exchange, you give up the dream of keeping a whole block and accept a steady stream of small payments instead. It is the difference between buying one lottery ticket and owning a slice of the ticket-selling business — smaller wins, far more often, with the variance smoothed into something you can plan around.

What a "share" actually is

Pools do not measure your work by blocks found — they measure it by shares. A share is a hash that meets a much easier difficulty target set by the pool. It proves you did the work, even though it is not good enough to win a block.

Think of it like this: the pool asks you to roll dice until you beat a 10. The network asks you to beat a million. Every time you beat a 10, the pool records a share. Most shares never win anything. But occasionally, one of your shares is so good it beats a million too — and that is a block, worth the full reward. The pool's job is to count all the 10s and divide the million fairly.

Your earnings scale with your shares, which scale with your hashrate. More machines, more shares, more of each block. The scheme determines how the counting turns into money — and, just as importantly, who bears the risk when the pool has a bad week.

PPS: the pool takes the risk

In Pay-Per-Share, the pool pays you a fixed amount for every accepted share, immediately, whether or not the pool has found a block. Your income is completely smooth. The pool absorbs all the variance — during unlucky stretches, it pays miners out of its own reserves.

That insurance costs money. PPS fees typically run 4–5%, noticeably higher than other schemes, because the pool needs a cash cushion to survive dry spells. It is the most predictable option and the most expensive one.

There is also a quieter cost: basic PPS historically covered only the block subsidy, not the transaction fees bundled into each block. Since the 2024 halving cut the subsidy to 3.125 BTC, fees have become a meaningful slice of block revenue — sometimes 10–15% during congested periods. A scheme that excludes fees quietly costs you that slice.

FPPS: PPS plus the transaction fees

Full Pay-Per-Share fixes the fee problem. You get the same fixed per-share payment as PPS, plus a proportional share of the transaction fees in each block, usually averaged over a recent window. It is the closest thing to the theoretical maximum a miner can expect per unit of hashrate.

FPPS is the most popular scheme in industrial Bitcoin mining as of 2024–2025. Foundry USA and Luxor run FPPS-style payouts, and fees typically sit around 2–3% — lower than old PPS because the fee market is more predictable than it used to be.

For most miners, FPPS is the default sensible choice. It is boring in the best way: your earnings track your hashrate, the pool handles the variance, and you keep the fees. The only miners who should look past it are those running at real scale, where shaving a percent off the fee is worth managing the variance themselves.

PPLNS: the rolling window

Pay-Per-Last-N-Shares works differently. The pool pays nothing until it finds a block, and then it splits the reward among the miners who submitted shares in the recent window — the last N shares, regardless of round boundaries.

Your income swings more. If the pool gets lucky, you earn more than FPPS would have paid. If the pool hits a dry spell, you earn nothing at all for days. The pool bears no variance risk, so fees are lower — typically 1–2%.

The window has one important side effect: it punishes pool-hopping. If you leave the pool during a dry spell, your shares age out of the window and you forfeit the payout you were building toward. PPLNS rewards loyalty by design. AntPool, F2Pool, and ViaBTC offer PPLNS or hybrid options for miners who want to ride the variance.

Over long horizons, a large pool's luck averages out and PPLNS lands close to FPPS minus the fee difference. The question is whether your cash flow can survive the ride.

PPS+ and the other hybrids

PPS+ splits the difference: the block subsidy is paid on a PPS basis (guaranteed), while transaction fees are distributed on a PPLNS basis (only when blocks are found). The logic is straightforward — the pool insures you against variance on the predictable part of the reward, but not on the part that itself swings wildly.

Whether PPS+ beats FPPS depends on the pool's luck over your time horizon. In an unlucky stretch FPPS pays more; in a lucky one PPS+ pays more; over years the gap mostly washes out. ViaBTC offers a choice of PPS+ or PPLNS at around 4%, and some smaller pools run PPS+ at 1–3%.

Older schemes like pure proportional (split each round's reward by share count) have nearly died out because they were vulnerable to pool-hopping — miners would join early in a round when shares were scarce and leave late. Score-based schemes decayed similarly into obscurity.

What pools actually keep

The advertised fee is only part of the story. The bigger question is how the pool treats transaction fees. Some pools quietly keep all transaction fees and share only the "naked" block subsidy with miners. You think you are paying 1%; in reality the pool may be keeping 10–20% of your potential profit in fee revenue.

This is the single most important line to read before joining a pool. Look for explicit wording that you are paid all transaction fees, and check whether they are included in the quoted payout. A 0% PPLNS pool that keeps the fees can easily cost more than a 2% FPPS pool that shares them.

Other things that eat into earnings: minimum payout thresholds (small miners can wait weeks for payment, during which their bitcoin sits in the pool's custody), stale shares from high ping to the pool's servers, and tiered fees that quote one rate but charge large operations less.

How to pick without overthinking

For a home miner or small operation, FPPS at a reputable large pool is the default answer. It is predictable, it includes fees, and the 2–3% cost is honest.

Consider PPLNS if you mine at meaningful scale, can tolerate uneven payouts, and plan to stay put for months — the lower fee compounds. Avoid hopping between pools on emotion; on PPLNS, switching during a dry spell destroys returns you already earned.

And before you optimize the scheme, optimize the basics: cheap electricity, decent uptime, and a pool with servers near you. The payout scheme might change your earnings by a percent or two. Electricity changes them by everything.

One more thing worth knowing: a handful of pools control most of Bitcoin's hashrate. Foundry USA and AntPool have each at various times held 25–30% of the network, and the top four or five pools together routinely exceed half. In practice the risk is softer than it looks — a pool is thousands of independent miners who can redirect their machines in minutes if an operator misbehaves — but you are not just choosing a fee structure. You are choosing which slice of the network's coordination layer to support.

Mining pools did not make mining profitable. They made it predictable — and predictability is what turns a lottery ticket into a business. The scheme you choose is just the price you pay for how much of the risk you want someone else to carry.