Centaur Vinecrasher without a -1/-1 counter on it).
Easy Prerequisites
There are at least one land card in all graveyards.
Steps
Activate
Goblin Bombardment by sacrificing
Centaur Vinecrasher.
When
Centaur Vinecrasher dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its replacement effect.
Resolve the
Goblin Bombardment ability.
Repeat.
Results
Infinite ETB.
Infinite LTB.
Infinite damage.
Infinite death triggers.
Infinite sacrifice triggers.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).