Abapa

Abapa is the codified competitive form and the version played here unless you choose otherwise. Everything on the rules page applies as written, and the grand slam is handled gently: you may make the move, but you take no seeds for it.

So you cannot finish an opponent off with one clean sweep. Grinding their row down is still strong, because they end up shuffling one or two seeds while you build, but the last blow has to be earned over several turns. A defender who is nearly out is never quite dead, which keeps long endgames tense.