Im also a student (no expert yet). I guess the one with the valid block in the end gets the reward. Maybe both get the reward registered in the beginning, but ones the transactions goes back to the mempool the reward is withdrawn (or not completed, hence the 6 confirmations). The reward probably isn’t dealt to the miner until fulfilling 6 confirmations, so it is like a normal transaction, but it hasn’t completed all 6 confirmations yet.
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It is inded as @ludvighatle explained 
the mining reward or coinbase is basically just a special kind of transaction in the block. So if the block is dropped so is the reward.
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[quote=“ivan, post:1, topic:8434”]
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What happens in the bitcoin network when two miners solve a block at the same time?
When this occur it is more or less like a stalemate and the decision on the miner that will be retained on the blockchain will be determined on the next mined block and on which of the two blocks that next miner appends his block.That will serve as the longest blockchain and eventually the other block that didn’t get a next appended block will eventually be dropped back into the Mempools with all it’s transactions. -
What is a stale block? A stale block is a valid mined block attached previously to the blockchain but get dropped off back into the Mempool.
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How do stale blocks occur?
A stale block occur when two Miners append there mined block at the same time on the blockchain. This create two version of the same truth. -
Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
To prevent the transaction being attached to a stale block which will eventually be dropped back into the Mempool and to allow for nodes synchronisation of the transaction across the network and prevent such transaction ending up in a stale block.
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- The continued growing of the chains will decide the truth. The longest chain survive and the new blocks of the shorter chains will be returned to the mempool.
- A stale block is a block on a shorter chain that is put back in the mempool.
- It occurs when another chain gets longer and being accepted by the blockchain.
- It is recommended to wait for 6 confirmations to be sure that the block with the transaction is not a stale block.
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1.Miners compete with each other trying to solve a cryptographic puzzle. It could happen that two miners from different part of the world create a block at the same time. Having Nonces and transaction validated, it is created a two different versions of the blockchain. It all depends on how efficient the miners are in order to solve the puzzle. A new miner could attach a block to one of the blocks creating a longer blockchain ( The blockchain with more POW, not necessary the amount of blocks). As a result the other block will be dropped and send the transactions to the Mempool.
2.Stale blocks are also known as Orphans blocks. They are blocks that were in the blockchain once . Blocks that were dropped because another version of a blockchain was longer.
3.It could occur if the 10 minutes block time is not properly used. To minimize the issue with orphans blocks, they are propagated every 10 minutes. Blocks coming out in a fast way means that the block is not able to propagate to the entire network before a new block is out. As a result, the new Block is being propagated before the previous one. “Promiscuity” of blocks provoke competition with each other. In fact, one of them might be dropped.
“The information needs to travel physically trough out the world”
- They will both propagate their block throughout the blockchain. By chance the longest block (where other miners link their block to that is also a valid block will be the one truth. That truth is determined every 10 minutes. The other block (of the shortest chain) becomes a stale block
- see 1.
- see 1.
- Because you still run in to the chance that your transaction’s block ends up becoming a stale block.
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- The blockchain could temporarily fork
- A legit block that will be removed because of forks with more POW; its TXs will be put back in the mempool
- As a result of fork resolution
- To be sure your TX won’t be in one of the orphaned block
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- When two miners solve a block at the same time, both the miners will propagate their new blocks to the network. The nodes that are geographically close to each miner will get their respective block first and the miners here will start mining on this new blockchain. The first of the blockchain that gets a new block mined after this “wins” (this is measured in terms of total hash power used for the blocks), and the blocks that are left by the “loser” miner is called staled blocks and the transactions will go back to the mempool.
- A stale block occur when two miners mine a new block at the same time and propagate the blocks to the network. The network can only accept one of the blockchains and the blockchain that is not accepted contains new blocks that will not be used in the final accepted blockchain. These blocks are called stale blocks.
- A stale block occurs when two miners mine a new block at the same time and only one of the blockchains can be accepted. The blocks that are left behind are called stale blocks.
- It is important to wait for more than one block to be confirmed when sending or receiving a transaction because you have to be sure that the transaction was not part of a stale block.
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- What happens in the bitcoin network when two miners solve a block at the same time?
Both blocks get added to the blockchain, so now you have two versions of the truth, the one that is appended to first will be the longest now and the other one will be discarded and transactions in that block will be returned to the mempool
- What is a stale block?
The stale block is the block that is discarded and the network will ignore this block
- How do stale blocks occur?
Two miners at the same time solving a block one gets discarded and is no longer part of the network (stale)
- Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
To be sure the transactions are accepted, the more confirmations the longer the chain and to bes ure the block is not dropped (stale)
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For some time there are two valid BC.
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A valid block not a part of BC (anymore) with the contents returned to MP is named “stale block”. (stale meaning dead)
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It was once appended to the BC as one of the two different valid BCs, but as the BC developed along the other valid copy, the BC will remove the block and return the transactions to the mempool.
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If you wait for some time, the probability for your transaction being a part of the true(est) BC increases. After six succeeding blocks, the probability of “yours” being included is close to 100%.
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There will be two versions of the blockchain and some miners will choose one or another, eventually the fork that has more pow will become the source of truth and the stale blocks will return to the mempool
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A block that has been discarded by a longer blockchain.
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When two miners solve the cryptographic puzzle at the same time. It is basically a race condition.
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To avoid the issue of race conditions and to ensure that all nodes have agreed on the correct version of the blockchain
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- What happens in the bitcoin network when two miners solve a block at the same time?
The block with the longest and deepest chain is accepted n the other blocks info goes back to the Mempools - What is a stale block?
A block that is disregarded - How do stale blocks occur?
The longest and deepest block chain is accepted and other disregarded blocks info are stale or given back to mempool - Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
There is a possibility that the block carryng your transaction can turn out to be stale and not proceed as expected
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A split in the chain is made
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It is the block or blocks that loses the PoW battle and gets put back into the mempol.
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They occour when 2 miners mine a block at the same time. Both versions of truth is then propagated through the global network until the chain with least PoW is discarted, creating a stale block.
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To be 100% sure that the transaction is in the blockchain and not a stale block.
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While this is indeed a reason why blocks are mined every 10 min, it is not the reason why stale blocks occur you have the answer in your first reply 
You also forgot to answer the forth question
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To minimize the issue with orphans blocks. Blocks coming out in a fast way means that the block is not be able to propagate to the entire network before a new block is out. It needs to wait 6 blocks in order to be confirmed.
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sorry!! I totally miss it. I already responded the 4th question. Thank you for your help!
have a good day
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- What happens in the bitcoin network when two miners solve a block at the same time?
Both miners start propagating their respective new blocks, and some nodes accept the new block of miner A while other nodes accept the new block of miner B. At some point, a miner confirms a new block based on either A or B. In this example, let’s say based on A. The resulting new block A+1 shows higher proof of work than the block B. Hence, block A+1 is commonly accepted as the new valid block and block B remains as stale block (it’s transactions need to be returned to the mempool).
- What is a stale block?
As described above, a stale block is a block that is not incorporated into the currently valid blockchain at any point in time. The block will need to be abandoned and the transactions of this stale block to be processed in new blocks.
- How do stale blocks occur?
See above.
- Why is it important to wait for more than one block to be confirmed when sending or receiving a transaction?
This is important so to minimize the risk of the transaction being incorporated in a stale block. The more blocks that follow upon the block of any specific transaction, the lower the probability that the transaction is in a stale block. It is common practice to await 6 confirmations to consider a transaction to be immutably confirmed.
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- A stale block is created. 2. A stale block is one that ultimately is rejected from the blockchain. 3. Stale blocks occur when two miners simultaniously start a new block on the blockchain. 4. in the case of a stale block occurance.
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When two miners solve a block at the same time, the miner whose block will be confirmed will be the miners block where another miner attaches a new block , as the network will always choose the longest chain of PoW.
A stale block is block that is valid but was rejected because of the above issue. All the tx go back tho the Mempool
It is important to wait for more than one block ( normally 6) because the information has to be transmitted to the global network . It is to minimise the issue of stale blocks.
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both miner will spread the block to the network of nodes. The longest chain will be the will be main blockchain. The other block is consider a slate and all transactions in the slate block will return to the mempool.
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It is a block in the blockchain but dropped because it is not in the longest chain.
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They occur when two miners mine a valid block approximately at the same time.
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To ensure your transaction is not in a slate block.
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