Transaction Ordering in a Block

[jmasterson]

How is a transaction being ordered inside a block? Looking at the blockchain.info explorer, I'm wondering, if you want your transaction to be in the first in the list (except for the mined block reward), can you control it?

I'm asking this because I'm planning to make a betting game where players will bet on who's transaction are first in the list. Can you control it if you want your transaction to be first in the list? Or is this purely on the miner's prerogative? Or even them can't control how the transactions are ordered in a block?

[DannyHamilton]

How is a transaction being ordered inside a block? Looking at the blockchain.info explorer, I'm wondering, if you want your transaction to be in the first in the list (except for the mined block reward), can you control it?

I'm asking this because I'm planning to make a betting game where players will bet on who's transaction are first in the list. Can you control it if you want your transaction to be first in the list? Or is this purely on the miner's prerogative? Or even them can't control how the transactions are ordered in a block?

Mining pools and solo miners have control over the order of the transactions in their blocks.

This means that a mining pool can place a bet in your game, and then they can create a block that makes sure that they win.

[jmasterson]

How is a transaction being ordered inside a block? Looking at the blockchain.info explorer, I'm wondering, if you want your transaction to be in the first in the list (except for the mined block reward), can you control it?

I'm asking this because I'm planning to make a betting game where players will bet on who's transaction are first in the list. Can you control it if you want your transaction to be first in the list? Or is this purely on the miner's prerogative? Or even them can't control how the transactions are ordered in a block?

Mining pools and solo miners have control over the order of the transactions in their blocks.

This means that a mining pool can place a bet in your game, and then they can create a block that makes sure that they win.

Can I ask how many times the biggest mining pool wins a block everyday?

[DannyHamilton]

How is a transaction being ordered inside a block? Looking at the blockchain.info explorer, I'm wondering, if you want your transaction to be in the first in the list (except for the mined block reward), can you control it?

I'm asking this because I'm planning to make a betting game where players will bet on who's transaction are first in the list. Can you control it if you want your transaction to be first in the list? Or is this purely on the miner's prerogative? Or even them can't control how the transactions are ordered in a block?

Mining pools and solo miners have control over the order of the transactions in their blocks.

This means that a mining pool can place a bet in your game, and then they can create a block that makes sure that they win.

Can I ask how many times the biggest mining pool wins a block everyday?

At the moment, the largest pool is probably F2Pool with about 21% of the global hash power.

As such, they should solve approximately 21% of the blocks per day.

There are on average 144 blocks solved per day.

21% X 144 = A bit more than 30 blocks per day.

[jmasterson]

How is a transaction being ordered inside a block? Looking at the blockchain.info explorer, I'm wondering, if you want your transaction to be in the first in the list (except for the mined block reward), can you control it?

I'm asking this because I'm planning to make a betting game where players will bet on who's transaction are first in the list. Can you control it if you want your transaction to be first in the list? Or is this purely on the miner's prerogative? Or even them can't control how the transactions are ordered in a block?

Mining pools and solo miners have control over the order of the transactions in their blocks.

This means that a mining pool can place a bet in your game, and then they can create a block that makes sure that they win.

Can I ask how many times the biggest mining pool wins a block everyday?

At the moment, the largest pool is probably F2Pool with about 21% of the global hash power.

As such, they should solve approximately 21% of the blocks per day.

There are on average 144 blocks solved per day.

21% X 144 = A bit more than 30 blocks per day.

does it cost them anything to change the order of transactions instead of the default order?

[DannyHamilton]

does it cost them anything to change the order of transactions instead of the default order?

Just the small amount of time that it takes a talented computer programmer to modify the code that the pool uses to build their blocks.

[jmasterson]

does it cost them anything to change the order of transactions instead of the default order?

Just the small amount of time that it takes a talented computer programmer to modify the code that the pool uses to build their blocks.

i guess they won't bother since i'm creating a very small game so it won't be too big deal for them thanks

[DannyHamilton]

does it cost them anything to change the order of transactions instead of the default order?

Just the small amount of time that it takes a talented computer programmer to modify the code that the pool uses to build their blocks.

i guess they won't bother since i'm creating a very small game so it won't be too big deal for them thanks

In addition to solo miners and mining pools having full control over exactly where transactions appear in their blocks, it is also possible for an individual to influence where in a block their transaction will appear if they know the transaction sorting rules that the largest pools use.

[S4VV4S]

I don't know if you would be interested but the new version of VPNCoin wallet will have a P2P lottery system that allows anyone to create a lottery.

If you are interested then check out their announcemnt(s):
https://bitcointalk.org/index.php?topic=789961.msg10979898#msg10979898
https://bitcointalk.org/index.php?topic=789961.msg11091075#msg11091075

Keep in mind that the new version is not released yet but will be soon.