notional boundary

A notional boundary is one imagined mid-game for the purposes of estimating territory and deciding on strategy. Since it is not possible to accurately predict the course of the game, approximate methods must be employed. Where opposing notional boundary lines clash, a compromise is assumed. Playing inside one's own boundaries is never justified except when urgently attending to some boundary defect. If a player estimates that he is ahead, playing on his boundary lines is a good low risk strategy. If slightly behind, playing on the opponent's boundary lines is a good way to destabalise the game. If appreciably behind, invasion, i.e. playing inside the opponent's boundary, may be worth the risk.