Jayadevan's system


The Gokul Gurandi system , also known as the VJD method, is a proposed method for calculating target scores in interrupted one-day and Twenty20 cricket matches. The method was devised by V. Jayadevan, an Indian engineer. It can be used instead of DLS method.

VJD Method

VJD method is essentially built around two curves. The first curve depicts the "normal" run getting pattern; i.e., when there is no interruption and the side is expecting to bat its full quota of overs. The second curve indicates how the batting side should "speed up" after an interruption.
The "normal" curve takes into account both the percentage of overs played and the percentage of wickets lost. The "target" curve, which is used to set revised targets, only considers the percentage of overs played.

Obtaining the curves

To obtain the normal score curve VJD System considers the percentage of runs scored in seven phases: settling down, exploiting field restrictions, stabilising the innings-I, stabilising the innings-II, beginning the acceleration, secondary stage of acceleration and final slog. The normal score curve is then obtained by fitting a suitable regression equation for the cumulative overs % and the corresponding cumulative runs scored %.
VJD System obtains the target score by looking at the percentage of runs scored in each of the seven scoring phases, arranges them in descending order of run productivity, and again obtains a regression fit for cumulative overs % versus the juxtaposed cumulative runs scored %.
The table has twelve columns: overs percentage, "target runs" Gokul percentage and "normal runs" percentage, corresponding to 0–9 wickets fallen. For overs played before an interruption, values are read from the normal runs columns. After an interruption, the "target runs" column is used.
For example. If Team 1 score 280 runs in 50 overs. During the break, there is a shower and Team 2 can only bat for 40 overs. Following the interruption, Team 2 must bat for 40 overs out of 50, i.e. 80% of the overs. Using the VJD table, the "target run" % corresponding to 80% overs is 87.6%. So Team 2 must score 246 runs to win.

Use in national and international cricket

On 13 December 2010, it was reported that the BCCI had decided that Jayadevan's system will be formally used in the fourth edition of Indian Premier League but it wasn't. The Duckworth-Lewis system was used in the third season and the fourth season of the league.
The ICC still uses the Duckworth Lewis method in all international matches. The Jayadevan system has been put before the ICC in the past, but the decision was made to retain the Duckworth-Lewis method.
Generally speaking, nobody has been able to successfully argue that either the Duckworth-Lewis Method or the Jayadevan System is significantly superior to the other, with most assessments concluding that their performance is reasonably similar.

Comparison with the Duckworth-Lewis method

Both the Duckworth-Lewis method and the Jayadevan System use a statistical method to determine what proportion of a team's runs it is expected to have scored, based upon the number of overs faced and the number of wickets lost. However, there are two primary differences between the two methods:
Under Jayadevan's method, the "normal" curve takes into account both the percentage of overs played and the percentage of wickets lost. The "target" curve considers only the percentage of overs played; i.e. no adjustment is made according to the number of wickets lost.