Why speed does not let Bismarck defeat an R-class escort

Could Bismarck use speed and range to destroy a convoy guarded by an R-class battleship?

Speed lets Bismarck avoid the fight, but the escort need not chase; to reach the merchants, the raider must enter the battleship's effective range.

The theoretical maximum-range advantage matters less than practical gunnery range and target effect. At very long range Bismarck cannot reliably batter a heavily armored R-class ship, while closing risks crippling damage that a surface raider cannot repair. Speed lets the German ship decline combat, but not reach the merchants while their escort remains between them. The watch point demonstrates how mission and tactical geometry can neutralize a paper performance advantage.