What decides about the position in the block? [duplicate]

Question

All these transactions happened within the single block:

Source: https://etherscan.io/defi?q=0x8a40c222996f9f3431f63bf80244c36822060f12#dextracker

Right now it is still possible to get to the initial transactions, after some time Etherscan will not probably limit to the last 10000 transactions or so.

So here is transaction on top 2000 GWEI: https://etherscan.io/tx/0x62dd2e053fefb5a857a3869391fab0b9ba8f474347bf2b26269138e3fec52292

And here is transaction on the bottom 2000 GWEI too: https://etherscan.io/tx/0x7582b5ac833e80c30baeb2f7e8fd0233c42f978a8b8f319871267e78f4b7032b

Both were mined in the the same block, both had the same gas price. One massively in the profit. One hardly profitable.

What decides about the position in the block?

• Gas price?
• First to be seen by the miner?
• Some other factors?

Bonus question: Is 2000 GWEI some hardcoded number, noticed loads of guys using specifically that amount?

Answer 1

If you search this site there are multiple questions which ask the same thing but from a bit different angle, so I couldn't find an exact duplicate for your questions, although my answer has all the same data as those answers.

The transaction order in the block is entirely up to the miner to decide. And because they can decide it, they typically choose an order which gives them the biggest reward, so they sort the available transactions according to the used gas price and include as many as they can. That way they maximize their rewards.

However, that is just the theory. Mostly things work like that, but then there are other alternatives. The miner may have other motives besides getting the highest gas price per transaction: he may get compensated in other ways for including a certain transaction in his block. For example someone may offer him X dollars (outside the blockchain) for including certain transaction in a certain way.

Since one miner only controls a small part of the network's hash rate, there are no guarantees when a transaction gets included in a block, but the miners can influence it - so it's all about probabilities. And miners can form mining pools which can influence things even more.

Here is one public tool, which offers service to get your transactions processed in a certain way (without specific gas pricing): https://github.com/flashbots/pm/blob/main/guides/flashbots-alpha.md . There are other similar things out there - you should read some articles of MEV (Miner Extracted Value).

About your bonus question - no idea.