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Thursday, April 10, 2014

the rain-rule in Cricket - BCCI adopts VJD (Jayadevan) method (no Duckworth-Lewis) !!

The T20 WC is over –Yuvi’s  21 ball struggle in the finals made him the villain – and in a week from now, IPL version 7 will be on – there is hope for turnaround for the highest paid batsman as also for many others staking claim including – Manoj Tiwary, Ambati Rayudu, Saurabh Tiwary, Cheteshwar Pujara – Virender Sehwag, Gautam Gambhir, Dinesh Karthik and more……..every IPL has thrown new players in the reckoning, though some have faded faster than they emerged.  The 2014 season of the Indian Premier League, abbreviated as IPL 7 with  Mumbai Indians being the defending champions will start on 16th Apr.  The opening 20 matches will be held in the UAE at three different stadiums in Abu Dhabi, Dubai and Sharjah with the tournament returning to India on 2 May. ~ this is no post about IPL – but something from domestic Cricket, which you most likely would not have noticed. 

When India played at Hamilton recently, Newzealand made  271 for 7 (Williamson 77, Taylor 57) in 42 overs – chasing that,   India  made 277 for 9 (Kohli 78, Dhoni 56, Southee 4-72) in 41.3 overs ~  yet Kiwis won…. ….. at end of over 41 – Indians were 275/8 … and 22 were required off 6 …. Yes, it was the field game, but one played using maths tables and calculating tools …. Culminating in NZ win by 15 runs. 

The names of Frank Duckworth & Tony Lewis are known  to every Cricket fan.  It is the rain rule or rather how scores will be calculated when it rains in the midst of a match.  Rain rules are indeed strange; the revised targets generally favour the chasers as they have the job cut out in the shortened version. The Duckworth–Lewis method (often written as D/L method) is a mathematical formulation designed to calculate the target score for the team batting second in a limited overs match interrupted by weather or other circumstances. The D/L method  devised by two English statisticians, Frank Duckworth and Tony Lewis was first used in the ICC Trophy in Malaysia in 1997 and in 1998 was applied in New Zealand, South Africa, Pakistan, India and West Indies.

The previous rain-rule was even worser …. On  22nd Mar 1992  - SA  which had defeated Australia, West Indies, Pakistan, India and Zimbabwe were chasing  253 – rain  interrupted play for 12 minutes with South Africa 231/6 off 42.5 overs and the over limit was reduced to 43 overs with the target reduced by 1 to 252. So suddenly when it rained, the target became 21 off a single delivery….. !!!!

Without getting into more statistics, for sure, the fans would love the game being decided on the field and not by the mathematicians – more than a decade ago, V Jayadevan, an engineer from Kerala had prescribed another version taking into account the statistics from the games played in the past. This was adopted in the rebel Indian Cricket League. At the time of heavy International Cricket (Asia Cup & T20 WC), with IPL due, not many would have read about Goa pulling off a 7 wicket win over Tamil Nadu in Mushtaq Ali T20 South zone tourney at Vizag.  For long, only Karnataka and to a lesser extent Tamil Nadu and Hyderabad – dominated the South Zone – Andhra, Kerala and later addition of Goa were ‘also rans’.    On April 2, Goa moved to the top of South Zone table  with their 2nd win two matches beating last year runner-up Kerala by two runs in the Y S Rajasekhara Reddy-ACA-VDCA Cricket Stadium here today.    At at Dr PVG Raju ACA Sports Complex, Vizianagaram (reading such Stadium names, sad that Cricket in Tamil Nadu is not beyond Chepauk – why not have matches at Tirunelveli, Trichy, Madurai !) – Tamilnadu beat Andhra by 32 runs …………. in a match decided by rain rule. 

There was stoppage due to rain when Tamil Nadu were 39/1 in 6 overs ~ the match was reduced to 17 overs and the target revised to 159.  At the fort town of Vizianagaram, a four-wicket haul from left-arm spinner Rahil Shah gave Tamil Nadu a 32- run win by the V Jayadevan method, over Andhra in Vizianagaram. Sent into bat Tamilnadu made 157 for 7 and the target was revised by the new VJD method to 159.  Shah opened the bowling and took the first three Andhra wickets as they slipped to 19 for 3; eventually  Andhra were shot out for 126 with 10 balls remaining.

For those who noticed, the rain-rule was ‘VJD (Jeyadevan method) – the target matrix provided by a Kerala-based engineer. Analysis by independent experts of a number of recent One Day Internationals (ODIs) showed that the target set by the Indian method was closer to the real score in most cases, than what the ICC's Duckworth/Lewis method determined. The maker, V. Jayadevan, is  a Thrissur-based engineering researcher, and the  mathematical model is based on the natural development of an innings, through its various stages: settling down, making use of field restrictions, stabilisation, acceleration and final slog. Three broad categories of interruptions — usually because of rain — are catered for: between the innings; within the innings of the team batting first and within the innings of the team batting second. Multiple interruptions are also allowed. Based on the general scoring pattern of a team in limited-over cricket and the analysis of a large number of closely-fought matches, a `normal' statistical curve  has been  developed. This method used regression analysis using `spread sheet' software and the author determined that the scoring pattern of a team was best represented as a cubical polynomial equation. Mr Jayadevan has generated a `target curve' which tries to predict the number of runs that could have been scored had the `lost' overs been available. He also provides a `Target Table' — an easy look-up tool where the revised target can be computed depending on the percentage of total overs that were completed for different percentages of wicket falls.  Many experts after critically comparing this with DL method feel that Jayadevan method has the edge.

Sunil Gavaskar has been instrumental in giving Mr. Jayadevan an opportunity to present his method to the Board of Control of Cricket in India (BCCI) as well as to an Indian seminar attended by umpires and that happened ago.  Happy that the BCCI has adopted this method granting recognition to the work of VJD, finally taking him to a higher plane. Gavaskar as chairman of BCCI technical committee had invited Jayadevan for a seminar in 2000 itself.  Now Jayadevan ‘shines on rainy days’.

With regards – S. Sampathkumar

10th Apr 2014.

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