A comparison of Twenty20 bowling strategies between Powerplay and non-Powerplay overs

Abstract

This study compares the bowling strategy used in twenty20 county cricket between powerplay and non-powerplay overs. There were 15 matches from the group stages of the English twenty20 cup that were used to record the data. A computerised notational system called CRICKET-STAT was used to input the data. The data that was recorded was then broken down into 4 sections of variables of which were thought to show the biggest indicator towards bowling strategy employed by the fielding side. The 4 sections were bowler type, delivery type, line of delivery and length of delivery. The data from these variables were entered into a Shapiro Wilks test to determine if the data was normal. This showed that the data was not normal and so a Wilcoxon test was required to indicate the variables which showed significant differences (p<0.05) between powerplay and non-powerplay deliveries. It was concluded that bowlers employed in the powerplay overs were of a faster nature than bowlers outside of the powerplay, who were generally slower or spin bowlers. This then led to the deliveries in the powerplay being predominantly straight, and deliveries outside the powerplay being predominantly spin. The line and length of deliveries within the powerplay were relatively consistent as opposed to a high variation of deliveries bowlers used outside the powerplay. Delivery types were more varied outside the powerplay with an increase in bouncers and slower balls.