HawkEye Ball-Tracking Technology in Cricket — How It Works

HawkEye is a computer-vision system that triangulates the three-dimensional path of a cricket ball using multiple high-speed cameras positioned around the stadium. It was introduced into international cricket to power the LBW prediction element of the Decision Review System (DRS), providing a scientific basis for what was previously an entirely human judgment: where the ball would have gone had the batsman's pad not intercepted it.

How the six-camera system works

Six cameras are mounted at fixed positions around the ground, each filming at a minimum of 340 frames per second. By capturing the ball from multiple angles simultaneously, the system can calculate its exact three-dimensional position at every point in its flight. From the point of impact with the pad, HawkEye extrapolates the remaining trajectory using physics models that account for seam angle, swing, spin rate, and deceleration. The result is a 3D animated path displayed within seconds to the on-field umpires, the third umpire, and television viewers.

Pitching and impact zones

Before the DRS review can succeed, two earlier checks must pass. First, the ball must pitch in line — between leg stump and an extension of off stump. Second, impact with the pad must be in line — not outside the line of leg stump. If either check fails, the LBW review is declined regardless of where HawkEye shows the ball going. Only if both checks pass does the projected hitting-the-stumps prediction become decisive.

Umpire's call zone

HawkEye is accurate to within 5 mm, but that margin is enough to affect decisions at the edge of the stumps. To acknowledge this residual uncertainty, the ICC introduced 'umpire's call': if the ball is shown clipping the edge of the stump — defined as less than half the ball's width overlapping the stump — the original umpire's decision stands rather than being overturned. If the on-field umpire gave not-out and HawkEye shows only umpire's call overlap, the batsman survives; if the umpire gave out and HawkEye shows umpire's call, the batsman is dismissed. This preserves the on-field decision when the projection is at its least reliable.

HawkEye beyond LBW

Though best known for DRS, HawkEye data is used for a wide range of broadcast graphics: pitch maps showing where each ball landed across an innings, wagon wheels tracing the direction of every shot, speed graphs tracking a bowler's pace over an over, and predictive run-rate curves. Some broadcasters also use it to model swing paths and compare a bowler's leg-side drift with their previous spell.