Players who are in the game dont always see the game. Even a star like the great Reggie Jackson still needed a coach. Earl Weaver demonstrated this point when he managed Reggie for the Baltimore Orioles.
One of Weavers rules about base stealing was that runners had to have a signal before stealing. This upset Reggie because he had studied many of the pitchers and catchers in the league. He knew those he could steal against.
During one game Reggie stole a base without a signal, His technique was flawless. He certainly didnt expect the coach to disagree with his decision.
But Weaver pulled him aside and explained why there had been no signal. Reggies action, though successful, had actually helped the other team. By having first base open, the opponents had been able to walk the next man (a powerful hitter). That forced Weaver to use a pinch hitter to early in the game.
The coach trusted Reggies ability, but he also knew that it wasnt time to steal a base. The player had a limited view; the coach saw the whole game.