WTC final: Bad light in cricket - what is the device umpires use?

The final session of Day 2 of the World Test Championship (WTC) final in Southampton was curtailed midway due to bad light. On-field umpires Michael Gough and Richard Illingworth were seen taking a couple of readings from a small 'light meter' before halting play indefinitely.

Although it doesn't seem like sound logic to stop a game midway, bad light can be a major issue in cricket. The inability to spot the red leather ball can put the safety of batsmen, fielders and, to some extent, even bowlers, in peril.

Prior to 2010, the umpires used to depend on the advice of the batting side to decide on bad light. But it was considered overtly partial toward the batsmen - they could demand a halt when things weren't going their way - and was amended.

Since then, the umpires have the sole discretion on deciding upon stopping the play due to bad light. The light meter they carry now is a device with a light sensor at one end and a window at the other which displays the reading that indicates the current light conditions. The umpires usually stand at one end of the pitch and point it towards the sight-screen to take a reading.

Law 3.6.3 of the Marylebone Cricket Club (MCC) manual explains the use of these light meters as follows:

"Light meter readings may accordingly be used by the umpires: a) To determine whether there has been at any stage a deterioration or improvement in the light. b) As benchmarks for the remainder of a stoppage, match and/or series/event."

The reference point for measuring bad light is always their first reading. For instance, if the game was halted midway through Day 1 after a particular reading on the light-meter, the umpires would have to stick to it as the threshold for the rest of the game. That is, even if both the teams are happy with the light and want to continue.

Two riveting sessions preceded the WTC final's halt due to bad light

After Day 1 was washed out on Friday, Day 2 finally provided fans with some mouth-watering action. Three wickets fell before the bad light interrupted the game. Rohit Sharma and Shubman Gill gave India a brilliant start, Cheteshwar Pujara got out cheaply and now skipper Virat Kohli and Ajinkya Rahane are standing solid.

Neil Wagner, Kyle Jamieson and Trent Boult have all been among the wickets and the final session will define which team will nudge ahead with the advantage.