The epicentre of baseball's velocity movement smells like a gym, looks like a high-end camera store and sounds like an out-of-sync kick-drum, the arrhythmic beat provided by the thump-thump-thump of weighted baseballs being flung against a padded wall.

In a batting cage outfitted with high-speed cameras, data-tracking units and video monitors, a succession of pitchers pump full-throttle fastballs into catcher's mitts – then consult with an iPad-wielding coach to go over the results – while other athletes lift weights off to the side, and still others hurl colour-coded balls weighing between 100 grams and 1.8 kilograms (a standard baseball weighs 140 grams) into the wall from point-blank range.

Washington Post