The physics didn't change; the read did. BITE holds the seam almost shut for a beat of true stillness — the pause that makes everything after it land as force. FIGHT parts the seam and springs it back three separate times, each attempt landing a little further than the last rather than undoing the one before it. CRACK snaps the gap open in one jump, with a puff of grit off the valve as its grip actually fails. GIVE swings the rest of the way, faster than it fought, with a small overshoot before it settles — and that's the instant the shell either bursts into a cluster of amber motes with a Pearl inside, or, this time, nothing at all.
Worth restating here, because it's easy to miss if you only ever saw the old bar fill: a shell is not a one-time pickup and it is not guaranteed to pay out. Prise one and it closes for 15 minutes before it reopens right where it was — an endlessly replenishing faucet rather than a finite one, because Fusion spends Pearls whether it wins or loses, and a finite well feeding that would eventually run an unlucky pilot dry. And finishing a prise is a real coin flip weighted by depth — as low as a 5% empty chance in the Sealed Grotto, as high as 35% at the surface. An empty prise still pays the same +25 Pilot XP a full one does; the only thing it costs is the time you already spent watching the seam fight you. Full mechanics in the guide: Pearl Shells.