CoinSelect using multiple small UTXOs instead of one big

[ademcan]

Hi team, thanks for the great work. I realized that sometimes coinselect (Blackjack, with Accumulative fallback) is using multiple smaller UTXOs rather than one big, and therefore ends up with higher fees when sending BTC. Isn't it the idea of the default module to select the biggest UTXO first? Am I maybe using a wrong one?

[junderw]

Can you provide an example?

Since this library doesn't look at txid info etc. you can strip that data from the test data set so we can try it and see what's going on.

[Taweesakpintakam7m1]

Can you provide an example?

Since this library doesn't look at txid info etc. you can strip that data from the test data set so we can try it and see what's going on.

Hi team, thanks for the great work. I realized that sometimes coinselect (Blackjack, with Accumulative fallback) is using multiple smaller UTXOs rather than one big, and therefore ends up with higher fees when sending BTC. Isn't it the idea of the default module to select the biggest UTXO first? Am I maybe using a wrong one?

[spencerstock]

If blackjack is successful it will often result in higher fees. Blackjack isn't optimizing for low fees but for 0 change (ultimately reducing the amount of dust or small value UTXOs that will remain after the transaction)