da dobrowin： Balls per boundary, runs per over, and other key stats from the IPL over the years

da dobrowin： Gaurav Sundararaman03-Apr-2017Now in its tenth year, the Indian Premier League has evolved over time. Franchises have become smarter while picking teams as well as ensuring they have enough specialists in their squad. What do these specialists do? Most franchises look to pick players who perform a particular role during any of the three phases of an innings – the Powerplay (1-6 overs), the middle overs (7-15) and the death (16-20). Interestingly the average run rate across all the three phases in the last two seasons have witnessed higher run rates compared to previous seasons. Teams have looked to continuously attack and have been less circumspect than in earlier seasons.

Year 1 to 6 7 to 15 16 to 202008 7.7 7.98 9.942009 7.22 6.85 9.132010 7.89 7.56 9.582011 7.2 7.44 9.12012 7.22 7.39 9.522013 6.93 7.23 9.572014 7.54 7.74 10.032015 7.75 7.83 10.312016 7.7 7.85 10.16Each of these phases requires a unique skill, with a different key metric to measure success. Here are some of those skills, and the players who have topped the charts with bat or ball in each of those phases.The Powerplay

This phase is vital to set up the game for the batting team. With fielding restrictions in place during this phase, the onus is on the batsmen to score at a high strike rate. Bowlers who can prevent that and thereby leave the opposition with too much to do in the latter overs are obviously valued. The average Powerplay score in the last five seasons of the IPL is 43, while the average economy rate for the top 25 bowlers in this phase is 7.23.In the last five seasons, the batsman with the best strike rate in this phase is Faf du Plessis. He has a strike rate of 142.86 from 30 innings. David Warner and Virender Sehwag follow, with strike rates of 142.57 and 135.68. Chris Gayle is in seventh position with a strike rate of 128.29.Among the bowlers, only three have gone at a rate of less than six runs per over in the Powerplays. Sunil Narine tops the list with an economy rate of 5.33, by far the best in the IPL. Lasith Malinga and Dale Steyn are the other two who have gone at below six. Among the Indian bowlers in this phase, Bhuvneshwar Kumar is the best with an economy rate of 6.13.ESPNcricinfo LtdThe Middle overs

This phase is for teams to capitalise on a good start or rebuild after a poor one. With the field spread, it is important for batsmen to at least rotate the strike and minimise dot balls, even if they are not able to score boundaries. For the bowlers, this is a phase where the field is spread and it is difficult to bowl a lot of dot balls. Hence teams look for bowlers who take wickets during this phase; getting key opposition batsmen out during this period also limits the damage that can be inflicted in the last five.In the previous five seasons, AB de Villiers tops the list in this phase with a dot-ball percentage of 27.71. Ajinkya Rahane follows with a percentage of 29.17 while Virat Kohli is not too far behind at 29.92. Interestingly Chris Gayle, MS Dhoni, Shane Watson, Kieron Pollard and Yuvraj Singh are at the bottom of the pack as the only five batsmen to have a dot-ball percentage in excess of 40 in this phase.Among the bowlers, it is not a surprise that the spinners rule this phase. Nine of the top 10 bowlers, in terms of strike rate, are spinners. Royal Challengers’ Yuzvendra Chahal has been the best, taking a wicket once in every 18 balls. The second-best is Karn Sharma, with a wicket every 22 balls. The best fast bowler in this phase is Dwayne Bravo, who usually begins his spells after the tenth over – in the middle overs he takes a wicket every 27 balls.ESPNcricinfo LtdThe death overs

The last five overs are often the most important in a T20 game; it isn’t unusual for games to change dramatically in the space of a few balls during this period. Most franchises have specialists for this role, both with bat and ball. The key for batting specialists in this phase is the ability to hit big shots from their first ball, since there is hardly any time to settle in.The top three batsmen in this phase are IPL legends. AB de Villiers is by far the best in terms of balls per boundary (BpB) ratio, which is a key parameter in this phase of the game. He scores a boundary once every 2.89 balls in this phase, while Virat Kohli and Rohit Sharma follow with a BpB ratio of 3.53 and 3.64. MS Dhoni, who has finished so many games for his franchise, has a BpB ratio of 4.47 which is slightly above average.ESPNcricinfo LtdAmong the bowlers, the usual suspects top the charts. Sunil Narine leads the pack, conceding a boundary only once every eight balls, while Lasith Malinga and Chris Morris concede a boundary every seven balls. Both Narine and Malinga have been around for many years, which makes their death-bowling consistency even more commendable. They are also among the top five bowlers in terms of economy rate in this phase. Among the Indian bowlers, Bhuvneshwar Kumar is the best, conceding a boundary every six balls.