Cricket Technology Explained: Hawk-Eye, UltraEdge, Snickometer and DRS
How cricket's broadcast and decision technology works — Hawk-Eye ball tracking for LBW, UltraEdge/Snickometer for catches, Hot Spot thermal imaging, and the Decision Review System (DRS) that uses all these technologies to overturn umpire decisions.
Cricket's technology infrastructure for decision-making has transformed the sport since the 2000s. The Decision Review System (DRS) — introduced in Test cricket in 2009 and T20Is/ODIs subsequently — allows teams to challenge on-field umpiring decisions using a suite of technologies: Hawk-Eye (ball tracking), UltraEdge (edge detection), Hot Spot (thermal imaging), and Snickometer (sound detection). Together, these technologies have reduced umpiring errors and created a broadcast experience where viewers at home often know the correct decision before the on-field umpires.
Hawk-Eye: Ball Tracking for LBW
Hawk-Eye is a ball-tracking system that uses multiple camera feeds to reconstruct the three-dimensional path of the cricket ball — from the bowler's release through to impact with the pad or stumps. For LBW decisions, Hawk-Eye calculates where the ball would have travelled if not intercepted by the batsman's pad, projecting the ball's likely path to determine whether it would have hit the stumps. The LBW review process: on-field umpiring decision stands unless Hawk-Eye shows at least 50% of the ball would have hit the stumps ('umpire's call' maintains original decisions in marginal cases). Hawk-Eye's accuracy is estimated at ±2.5mm for ball positioning — precise enough for the technology to be trusted on stump-clipping decisions.
UltraEdge and Snickometer
UltraEdge (and its older equivalent the Snickometer) detects whether the ball contacted the bat or pad using real-time audio analysis. A high-speed microphone captures audio at the moment of ball-bat or ball-pad contact; UltraEdge produces a waveform display showing sound spikes — a spike coinciding with the ball passing the bat indicates an edge. The Snickometer (predecessor) processed audio more slowly and was used in broadcast analysis rather than live decisions. UltraEdge is the ICC-approved real-time edge-detection system used in DRS today. Edge detection is particularly important for caught-behind decisions (did the ball hit the bat?) and LBW decisions (did the ball hit bat before pad?).
DRS: How Reviews Work
Each team receives two DRS reviews per innings in Test cricket (one in white-ball formats). A review is retained if the on-field decision is overturned; a review is lost if the decision stands (including 'umpire's call' outcomes in LBW reviews — contentious, because 'umpire's call' means the technology is uncertain, but the batting team loses a review). The review process: team captain signals review → third umpire checks available technology (Hawk-Eye for LBW, UltraEdge for edges) → decision communicated to on-field umpires → umpire signals either 'original decision stands' or 'decision reversed.' The average DRS review takes approximately 90 seconds; complex LBW reviews with multiple technology checks can take 2–3 minutes.
Frequently asked questions
What is Hawk-Eye in cricket?
A ball-tracking system using multiple cameras to reconstruct the cricket ball's three-dimensional path — primarily used for LBW decisions. Hawk-Eye calculates where the ball would have travelled if not intercepted by the batsman's pad, showing whether it would have hit the stumps. The technology is accurate to approximately ±2.5mm. An LBW review is overturned if Hawk-Eye shows more than 50% of the ball would have hit the stumps.
What is the difference between UltraEdge and Snickometer?
Both detect edges using audio analysis — a microphone captures sound at ball-bat contact and produces a waveform; a sound spike coinciding with the ball passing the bat indicates an edge. The Snickometer (older) processed audio more slowly and was broadcast-only. UltraEdge is the modern real-time version approved for ICC DRS use — it produces waveform data fast enough for live review decisions. Both work the same way; UltraEdge is simply faster and more accurate.
What happens if a team runs out of DRS reviews?
They cannot review any further on-field decisions in that innings (except in Test cricket, where reviews are reset at the 80-over mark). Running out of reviews means accepting the on-field umpire's decisions for the remainder of the innings — a significant disadvantage if the team has been unlucky with previous reviews. Teams keep their reviews if successful; lose them if unsuccessful (including marginal 'umpire's call' LBW outcomes).