Every event has some sort of requirement. Vault has specific requirements for gymnasts to make the event finals, while the other three events have requirements for the composition of the routines. These are the requirements as listed in the 2017-2020 Code of Points.
Vault
Competing two vaults is only a requirement when a gymnast wants to make a vault event final. When two vaults are competed, they must have both a different entry and a different flight phase.
Uneven Bars
Each composition requirement is worth 0.5 towards the routine's start value.
Balance Beam
Each composition requirement is worth 0.5 towards the routine's start value.
Floor Exercise
Each composition requirement is worth 0.5 towards the routine's start value.
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