Build the Next Block
~3 min · Intro
Pack a model block. Space is limited. Fee per space wins — not arrival order.
A model of how miners choose — not live chain data, and not a wallet.
You’re the miner: scarce space, best fee-per-space wins.
Not first come, first served. Each payment takes some block space and offers a bid. Fill the page with the strongest bids per space — waiting longer does not win.
What you just saw
Miners prioritize fee per space (fee rate), not who arrived first. A small high-fee payment can beat a large low-fee one, and “stuck” often means it missed this block’s space cut.