{"id":955,"date":"2018-11-12T20:20:54","date_gmt":"2018-11-12T20:20:54","guid":{"rendered":"https:\/\/2miners.com\/blog\/?p=955"},"modified":"2018-11-12T20:21:16","modified_gmt":"2018-11-12T20:21:16","slug":"orphan-stale-uncle-blocks-in-bitcoin-and-ethereum","status":"publish","type":"post","link":"https:\/\/2miners.com\/blog\/orphan-stale-uncle-blocks-in-bitcoin-and-ethereum\/","title":{"rendered":"Orphan, Stale & Uncle Blocks in Bitcoin and Ethereum"},"content":{"rendered":"

Sometimes the reward for the found block can be lower than usual or there may be no reward at all. Are you interested in finding out why that happens? Then keep on reading, but make sure to read this article<\/a> first.<\/p>\n

<\/p>\n

\"\"<\/h2>\n

Blockchain<\/h2>\n

To many, there is no need to explain what the blockchain is, but let\u2019s take a closer look at the chain itself. In the Bitcoin network, a new block is created every 10 minutes, whereas in the Ethereum network it\u2019s every 14 seconds. Every new block contains information about the previous block. This is how the blockchain is organized \u2013 it\u2019s an index, just like a numbered list or an Excel table. No gaps are allowed. Number 1 is always followed by number 2 which is followed by 3 and then 4, and so on.<\/p>\n

Every node\/computer in the cryptocurrency network is connected with other nodes and constantly exchanges data with them. Let\u2019s say for example, that the last block in a cryptocurrency network is #100. This means that at that moment all miners worldwide are trying to solve the same block \u2013\u00a0#101. Once it is solved, a miner (or a mining pool) sends the solution to the network through it\u2019s node. In the course of a few seconds or even milliseconds, all nodes in the network get information about block #101. The block goes through the verification process to make sure there is no fraud, and then the nodes wait for the next block \u2013 #102.<\/p>\n

\"\"<\/p>\n

But what happens if two miners solve block 101 at the same time? Let\u2019s say, for example, there are 100 nodes in the network. Miner A solved the block a bit earlier and sent the information about the block to 60 nodes. Miner B finished later and sent the information to only 40 nodes. Does it mean that miner A wins against miner B? Not necessarily. Let\u2019s take BTC and ETH as an example.<\/p>\n

IMPORTANT<\/strong>. You can\u2019t steal a block solution that is not yours. Cryptocurrency networks are protected against this type of fraud. The block solution from miner A doesn\u2019t work for miner B, so the latter can\u2019t take credit for it.<\/p>\n

Types of Blocks in Bitcoin Blockchain<\/h2>\n

Ten minutes is an average block find time for Bitcoin. In reality, it can vary from a few seconds to even a few hours. For example, it may depend on how fast blocks are being processed or how fast nodes exchange data with one another.<\/p>\n

Miner A and miner B solved block 101 at the same time. 60% of nodes got the new block from miner A, while 40% got it from miner B. At this point both blocks are completely legitimate and valid. After that, miners that followed miner A found 2 more blocks, while miners that followed miner B found 3 more blocks.<\/p>\n

So which chain is the valid one? The solution is simple. Miner B\u2019s followers have a longer chain, so it\u2019s valid. Sadly, miner A\u2019s followers worked for nothing and don\u2019t get any reward for found blocks.<\/p>\n

\"\"<\/p>\n

Do you remember that the blockchain is organized in the form of an index? Block 101 found by miner B is added to the list, as well as the next 3 blocks found by its followers \u2013 102, 103 and 104. The block found by miner A didn\u2019t make it to the index. This block gets cut off and remains without a parent, so it is called an orphan block<\/i>. Good news is that it has 2 children \u2013 the two blocks that were found afterwards. Bad news is that these blocks are useless, so they are known as stale blocks<\/i>.<\/p>\n

In reality, nodes are unlikely to wait for so long. Once block 102 comes out following the disputable block 101, all the cryptocurrency network will switch to this chain and abandon the other.<\/p>\n

People often confuse orphan and stale blocks. It\u2019s because both types of blocks are useless to Bitcoin miners, as they don\u2019t bring any profit. These blocks are also known as reject\/rejected<\/i>.<\/p>\n

\"\"<\/p>\n

To sum up, there are three types of blocks in Bitcoin blockchain:<\/p>\n