In the last one year in Test cricket, Kane Williamson is the highest impact batsman in the world. He is also the only batsman to have produced two series-defining performances (against West Indies and Pakistan) in this time-frame.
Joe Root is the highest impact English Test batsman in the last five years ahead of Alastair Cook and Kevin Pietersen. In this time-frame, he is also the third-highest impact batsman in the world after AB de Villiers and Hashim Amla. (Min: 25 Tests)
MS Dhoni's batting failure rate of 40% in IPL 2015 is his second-worst in any of the IPL editions so far. His worst was in IPL 2012 where he had a failure rate of 41%.
Virat Kohli's Batting Impact in IPL knockouts/playoffs: 1.66 in 6 matches (50% failure rate).
Kohli's Batting Impact in the rest of his IPL career: 1.99 in 113 matches (36% failure rate).
Amongst the teams that have qualified for the IPL 2015 playoffs, RR have the least number of players (three players) in their squad who have given a tournament-defining performance in any T20 tournament. RCB have five such players, MI have six and CSK have 11.
The highest impact uncapped Indian players in IPL 2015 so far are: Yuzvendra Chahal, Harshal Patel and Shreyas Iyer.
The highest impact New Zealand players in Tests played in England are: Dion Nash, Chris Cairns and Daniel Vettori. All three of them produced a series-defining performance during New Zealand's tour to England in 1999 where they won the four-match Test series 2-1.
Parvinder Awana has picked up the third-most proportion of top/middle order wickets in IPL history (after Lasith Malinga and Ashish Nehra) but surprisingly still hasn’t got a game in IPL 2015.
If we take a minimum of seven innings as a qualification, then Virender Sehwag emerges as the lowest impact batsman of IPL 2015 so far.
THE SECOND-HIGHEST IMPACT BATSMAN IN TEST CRICKET
Peter May is the highest impact English Test batsman ever, above the likes of Hobbs and Hutton. He absorbed the maximum pressure (of falling wickets) in English Test cricket history.