Five straits the model can actually close, ranked by how often it does. Every figure is measured against the live escalation engine, not asserted: how often each gate shuts, how often it becomes a blockade, and which of the two terms — the will to close it or the means to keep it closed — is the one holding it back.
The engine sets a level per strait per round, and it is the lower of two terms: how badly the holder wants the strait shut, and whether it still has the ships, mines and coastal missiles to keep it shut. Willingness only ratchets up — a state that has been hit has less reason to reopen, not more. Capability is the only term that can fall, which is why a closure here is not permanent.