Recently I did a tweetstorm on the unfairness inherent in the Duckworth Lewis method (or any rain rule for that matter). The concept is that by truncating an innings arbitrarily in case of rain and then extrapolating the team’s score using a standard formula, an assumption is made that the team has been batting following the “average strategy”.
And this is unfair to both the batting and bowling team - knowing that the game can be truncated any time means that batting teams must remain cognisant of the “par D/L score” and bat accordingly. Bowling teams have to pursue the dual optimisation of restricting the team batting first below the “par D/L score” at all points in time, and also restricting the end-of-innings score below the target. So this means, for example, that teams have to rethink their strategies of holding their best bowlers for the end.
While I made this twitter argument (like most twitter arguments) without data, I was curious to see how different teams’ strategies are in the way they build their innings. To put it simply - there is a big difference in the way teams approach their innings.
I’ve used data from October 2015, since that’s when the current powerplay “regime” came into play. I’ve only considered games among the top 9 teams (World Cup participants minus Afghanistan). The graph shows the average run rate at the end of every 5 over block. The dashed red line is the “average curve” (across teams).
It appears that Australia and South Africa might stand to benefit the most from any rain rule because their scoring patterns is closest to the “average” of all teams (of course, Duckworth-Lewis usually uses outdated data, so they may not benefit by that much). They begin fairly quickly, accelerate in the second half of the powerplay and then hold the run rate consistently until the 45th over, after which they slog.
Pakistan’s curve is also similar to Australia or South Africa’s, except that they are behind the average at all points in time. Also behind average at all times are the West Indies and Bangladesh. These two teams have occasionally produced good ODI results, but on average their batting isn’t up to the mark.
While England are always ahead of the curve (they’ve been a spectacular ODI team since the end of the last World Cup), they have a noticeable dip in their run rate as soon as the first powerplay is finished. One way to look at it is that they make much better use of the powerplay than other teams. Another way to look at it is to wonder why they suddenly slow down, and if they couldn’t have continued hitting from over 11 onwards as well.
This dip after the powerplay is seen in the case of New Zealand as well - and they continue to decelerate till over 35 at which point they start accelerating slowly. Sri Lanka’s deceleration beyond the powerplay overs is even more stark, and they don’t make an effort to accelerate until the last five overs. A good case in point was their recent chase against Australia, where they raced to 112/0 in 15 overs (chasing 335), but then quickly slowed down and ultimately folding for 247.
India begin fairly slowly - pretty much not making use of the powerplay, but one feature of their batting is the continuous acceleration (no other team has a strictly increasing run rate curve like India). Also, India’s innings has a jerk (increase in acceleration) around over 35, indicating they start their slog much before other teams, who start slogging only in the last five or ten overs.
With such a diversity of batting styles, it is easy to see where arbitrarily truncating an innings in case of rain falls short.
I tried doing a similar analysis of teams’ bowling styles as well, in terms of the overall run rate conceded at the end of every five over block. While some teams are better than others in terms of how many runs they concede, the different isn’t significant enough to be interesting.