Adam Kilgore wrote a great story on Ryan Zimmerman’s arm, and while the Nationals third baseman has expressed confidence in his throw, Kilgore talked to a rival scout who didn’t sound so impressed. From the story:
“He looks the exact same to me,” the scout said. “He’s still laying it off. That’s the term you would use. … He wants to throw on the run and be athletic. When he has a routine play, it looks the same. If he feels freer, where’s the arm strength?”
Then the game started. In the second inning, Zimmerman fielded a routine groundball and fired a strong throw across the diamond. Later, Zimmerman snared a ball with his backhand and, from somewhere near the top step of the third base dugout, rifled an off-balance throw to first base.
That second play mentioned can be seen in the video below. You definitely have to have some confidence to pull that throw off.