Winning the toss on a cloudy morning

Our expert throws light on the pros and cons of the Duckworth-Lewis method in the T20 format of cricket.

In an ICC World Twenty20 match on May 3, England scored an impressive 191 in 20 overs, but still lost to West Indies who scored 60 in 6 overs to win by the Duckworth-Lewis (D/L) method.

West Indies won because their captain Chris Gayle did two things right: (a) he chose to field after winning the toss on a wet morning and (b) he launched a batting blitzkrieg when he came out to bat because he realized that rain was imminent.

Gayle chose (a) because it is now common knowledge that the truncated D/L method for T20 significantly favours the team batting second, and he chose (b) because things turn even more favourable for the team chasing if they have scored a few quick runs (preferably without losing wickets) before the rain comes down.

Imagine that it had rained before WI started the chase. WI would then have had to score 66 in 6 overs to defeat England’s mighty total of 191. It is a lot easier to hit 11 per over with batsmen free to throw their bats … than average 9.55 over 20 overs. That’s why the D/L verdict appeared unfair.

As it turned out, WI came out to bat, scored 30 for no loss in 14 balls … and then the rain came! This lowered the WI winning target further: they now had to score only 60 in 6 overs to win.

The trouble with the truncated D/L method (that assumes that the evolution of a T20 match is like the last 20 overs of a 50-over ODI match) is that the fine balance between ‘overs remaining’ and ‘wickets in hand’ breaks down, and the ‘overs remaining’ resource becomes much more valuable than the ‘wickets in hand’ resource. And if the team chasing has ridiculously few overs to bat (5 or 6, as in that Eng-WI match), then the D/L method sets a very low target because it attaches most of the value to ‘overs remaining’ ignoring ‘wickets in hand’.

What is the way out? The sensible recommendation would be to restrict the minimum overs required for a result to 10 (or even 8). If that is not possible, then we should NOT truncate the D/L curves; instead we should pretend that a T20 match evolves exactly like an ODI match but at a much faster pace.

By suitably ‘treating’ the full D/L curves, it would be possible to set a target of about 75 runs in 6 overs if a team is chasing 191. This seems far more realistic.

There is a second problem with the D/L method for T20: it does not factor in the advantage of field restrictions in the first 6 overs. In 50-over ODI matches, this advantage is compensated because of the greater likelihood of losing ‘valuable’ wickets. But, in the truncated D/L model, wickets are far less expensive and the chasing team is better served by going slam-bang even if a wicket or two falls in the process.

A reasonable solution to the D/L method’s 20-over dilemma might therefore be to come up with redrawn D/L curves, and, since the new targets might be rather stiff – especially if the match has a severe curtailment – we might suggest that the 6-over field restrictions will apply irrespective of the duration of the interruption.

With this solution, the decision to bat second would be based on genuine cricketing considerations and not irrelevant meteorological ones.