William Strunk was addressing all writers when he wrote:
“Vigorous writing is concise. A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. This requires not that the writer make all his sentences short, or that he avoid all detail and treat his subjects only in outline, but that every word tell.”
The batting coach was addressing all hitters when he said:
“Vigorous hitting is concise. A batter should take no unnecessary steps, his motions show no unnecessary movements, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. This requires not that the hitter make all his swings short or that he avoid all bad pitches, but makes every swing count.