// Search starts from ss+1 to allow referencing (ss-1). This is
// needed by update gains and ss copy when splitting at Root.
bestValue = search<Root>(pos, ss+1, alpha, beta, depth * ONE_PLY);
// Search starts from ss+1 to allow referencing (ss-1). This is
// needed by update gains and ss copy when splitting at Root.
bestValue = search<Root>(pos, ss+1, alpha, beta, depth * ONE_PLY);