When looking at Bitcoin unconfirmed transactions, I'm trying to distinguish between txs that are likely to confirm (whether that be in the first next block or in 2 hours) versus txs that are likely to be replaced, or never to confirm at all.
Obviously, txs with the opt-in RBF flag fall in the latter category.
But I guess there are other criteria, such as:
- having an extremely low fee, or even zero fee.
- Having lots of dust outputs.
- Depending on unconfirmed inputs.
Anything else I should take into consideration? What other factors could make a tx less likely to end up confirmed?
For example, besides dust output, do dust (i.e. many small) inputs make a tx less sure to confirm? (other than more inputs causing larger tx data, thus resulting in a lower fee when measured in satoshis per KB)