Hot Spot Technology Failure — Ashes 2013

Hot Spot technology was one of the DRS components that generated the most excitement when it was introduced. Using two infrared cameras mounted on either side of the pitch, Hot Spot detected the heat generated by friction when the ball made contact with the bat. In theory, it was a definitive edge-detection tool — physics-based, objective, and binary. Either the ball generated heat on contact, or it didn't.

The 2013 Ashes was the most high-profile Test series in the world — five Tests between England (then world number one) and Australia, in England. DRS was in use and both teams had access to reviews. Hot Spot had been used in previous Ashes series but the 2013 summer exposed its limitations comprehensively.

The problem centred on faint edges. A thick edge generated significant heat through sustained contact and showed clearly on Hot Spot. A thin edge — the kind that often produces an audible click but barely deflects the ball — generated insufficient heat to register. The technology could not reliably detect the very edges it was most needed for.

The most notorious incident occurred at Trent Bridge in the First Test. Stuart Broad, batting for England, was struck on the bat — a thick edge to Ryan Harris's delivery that flew to first slip where Michael Clarke took the catch. The ball clipped the outside edge unmistakably. Everyone in the ground, including Broad, knew it. Broad stood his ground.

Australia reviewed. Their review protocol required them to look at Hot Spot before committing. Hot Spot showed nothing — no heat signature. The Snicko showed a sound spike but Hot Spot was considered the primary edge-detection tool. Third umpire Tony Hill reviewed the evidence and, finding no Hot Spot mark, was unable to overturn the on-field not-out decision.

Broad scored 65. England drew Trent Bridge and won the First Test by 14 runs. It was one of the most consequential single umpiring decisions — or rather, technology failures — in modern Ashes history.

The 2013 Ashes series exposed significant flaws in the Hot Spot infrared technology used as part of the DRS system. Hot Spot uses infrared cameras to detect the heat generated by friction when the ball hits the bat. But during the series, it repeatedly failed to show edges that were clearly visible on regular camera replays and audible on audio.

The most notable failure involved edges off thick bats that simply didn't register on Hot Spot. The silicone-based tape that some batsmen applied to their bat edges — ostensibly for protection — was suspected of dampening the heat signature and making edges invisible to Hot Spot.

Shane Warne, working as a commentator, was vocal in his criticism, calling Hot Spot "a waste of time" and questioning why the ICC was relying on technology that could be beaten by a piece of tape.

The controversy led to a significant reassessment of DRS technology. Hot Spot was eventually phased out and replaced by the more reliable UltraEdge system, which uses audio rather than infrared to detect edges. The 2013 Ashes effectively killed Hot Spot as a viable DRS tool.

“Hot Spot is a complete waste of time. The technology doesn't work and the ICC need to accept that and find something better.”

“I obviously knew it hit the bat. Everyone knew. But if the review doesn't show it, I can't walk. It's the system.”

“The tape on the bat edges is being used to defeat the technology. That can't be acceptable under any interpretation of the Spirit of Cricket.”

“We have to accept that DRS evolves. Hot Spot was a good idea that had a fatal flaw. We've moved to better technology.”

The controversy was immediate and lasting. Australia's players were visibly stunned. Shane Warne, commentating on Sky Sports, called Hot Spot "a complete waste of time" and questioned the ICC's continued use of technology that could be defeated by a piece of bat tape.

Investigation revealed that silicone-based tape, applied by some batsmen to the edges of their bats ostensibly for protection, significantly reduced the heat generated by friction. The tape acted as an insulator, preventing the infrared cameras from detecting the contact. Manufacturers and the MCC were asked to investigate.

The ICC held an emergency review of Hot Spot's reliability and commissioned a technical report. The findings were damaging: Hot Spot had a significant false-negative rate for faint edges, particularly against bats with edge tape. The ICC began the process of replacing Hot Spot with UltraEdge, an audio-based system using advanced Snicko-style microphone technology.