Luck is a statistical indicator that reflects how quickly or slowly a mining pool finds a block compared to the mathematical expectation. This parameter often misleads beginners, especially when they see values above 100%. In reality, it is simply a display of the probabilistic nature of mining, a key process described in our miner’s glossary.
Simple Analogy: Coin Flipping
To understand the essence of luck, imagine flipping a coin. Probability theory says that on average, there will be 50% heads and 50% tails. But if you flip it 10 times, can you get 8 heads and 2 tails? Of course. In this short moment, your “luck” on heads was 80%, which is much higher than the theoretical 50%.
It is the same with mining. Finding a block is a probabilistic event. The network is configured so that with the current difficulty and the pool’s total hashrate, it should find, say, 10 blocks a day. But on one day it might get lucky and find 12 blocks. On another, it might be unlucky and find only 8. Luck measures exactly this deviation from the mathematical expectation.
How is Luck Calculated?
The formula is quite simple. The pool knows how many shares (proofs of work) on average it needs to send to the network at the current difficulty to find one block. Let’s call this “Expected number of shares”.
Luck = (Actual number of shares spent to find a block / Expected number of shares) * 100%
The results should be interpreted as follows:
- Luck < 100% (e.g., 80%) — this is GOOD LUCK. This means the pool found a block spending less effort (shares) than expected. It got lucky.
- Luck > 100% (e.g., 150%) — this is BAD LUCK. This means the pool had to do 1.5 times more work than expected to find a block. It was unlucky.
- Luck = 100% — this is the perfect mathematical average. The pool found the block exactly when it should have according to probability theory.
How Does Luck Affect Your Income?
And now the most important part: the impact on your wallet. It all depends on your pool’s reward system.
- For PPS and PPS+ systems, luck DOES NOT MATTER. In these systems, the pool pays you a fixed price for every share sent, taking all risks (both bad and good luck) upon itself. Your income will be stable regardless of the pool’s luck.
- For PPLNS systems, luck DIRECTLY AFFECTS income. In PPLNS, you receive a share of the actually found block reward.
- If the pool has good luck (it finds blocks more often than expected), payouts will be larger, and your income for that period will be above average.
- If the pool has bad luck (it cannot find a block for a long time), payouts will be smaller, and your income will temporarily drop.
It is important to understand that according to the law of large numbers, over a long distance (weeks, months), the luck of any large pool always tends towards 100%. Periods of “bad luck” are compensated by periods of “good luck”. Therefore, if you are mining on a PPLNS pool, do not panic over local luck spikes. Just continue mining, and over time your average income will align with the theoretically calculated one.
