Question: Who ghost-wrote the autobiography of the sacked English cricketer who was signed to the Rising Pune Supergiants for the 2016 season?

Context paragraphs:
Rising Pune Supergiants in 2016: The Rising Pune Supergiants (RPS) is a franchise cricket team based in Pune, Maharashtra, India, which plays in the Indian Premier League (IPL).  They were one of the eight teams that competed in the 2016 Indian Premier League and were captained by Mahendra Singh Dhoni.  This was their first season playing in the IPL.

Saurabh Kumar: Saurabh Kumar (born 1 May 1993) is an Indian first-class cricketer who plays for Uttar Pradesh.  He made his Twenty20 debut on 8 January 2016 in the 2015–16 Syed Mushtaq Ali Trophy.  In February 2017, he was bought by the Rising Pune Supergiants team for the 2017 Indian Premier League for 10 lakhs.

Washington Sundar: Washington Sundar (born 5 October 1999) is an Indian cricketer.  He is a left-handed batsman and right-arm off-spinner.  He has played for the India national under-19 cricket team as a Batsman.  He made his first-class debut for Tamil Nadu in the 2016–17 Ranji Trophy on 6 October 2016.  In 2017 he was selected by Rising Pune Supergiant as a replacement for Ravichandran Ashwin.  He made his Twenty20 debut for Rising Pune Supergiants in the 2017 Indian Premier League on 22 April 2017.  He was man of the match in IPL 2017 played between Mumbai Indians and Pune Supergiants, in which he took 3 wickets for 16 runs.  He holds the record for the best bowling figures in an IPL final 2017.

Kevin Pietersen: Kevin Peter Pietersen MBE (born 27 June 1980) is a former England international cricketer.  He is a right-handed batsman and occasional off spin bowler who currently plays for Melbourne Stars in the Big Bash League, the Quetta Gladiators in the Pakistan Super League as well as the Hollywoodbets Dolphins in the CSA T20 Challenge.  He had also been signed by the Rising Pune Supergiants for the 2016 season of the Indian Premier League.

KP: The Autobiography: KP: The Autobiography is the autobiography of England cricketer Kevin Pietersen, ghost written by Irish sports journalist David Walsh.  It was scheduled to be released on 9 October 2014.  The book will summarise incidents from Pietersen's early life in South Africa and his career with the England team, including his sacking from the England squad in February 2014.

Ankush Bains: Ankush Bains (born 16 December 1995) is an Indian U-19 cricketer who plays for Himachal Pradesh and India U-19 as a wicket keeper.  He was signed up by Chennai Super Kings for IPL 2015 at his base price of 10 lakhs.  He was currently bought by new team "Rising Pune Supergiants" for Rs.10 Lakhs

Ravichandran Ashwin: Ravichandran Ashwin (   ; born 17 September 1986) is an Indian international cricketer.  An all-rounder who bats right-handed and bowls right-arm off break, Ashwin plays for Tamil Nadu in domestic cricket and the Rising Pune Supergiants in the IPL.  He is the fastest Indian bowler to reach the 50-, 100-, 150-, 200-, and 250-wicket mark in Test cricket.  In 2016, he became the only Indian after Rahul Dravid and Sachin Tendulkar to win the ICC Cricketer of the Year award.

Ankit Sharma (cricketer): Ankit Sharma (born 20 April 1991) is an Indian cricketer who plays as a spin bowler for Madhya Pradesh in domestic cricket.  He is a left-handed batsman and a slow left-arm orthodox bowler.  He is also a member of the Rising Pune Supergiants team in IPL.

Imran Tahir: Mohammad Imran Tahir (Urdu: ‎ ; born 27 March 1979) is a Pakistani-born South African cricketer.  A spin bowler who predominantly bowls googlies and a right-handed batsman, Tahir currently plays for the Proteas and the Lions in South Africa and Derbyshire in English county cricket.  He also represents Rising Pune Supergiants in the Indian Premier League.

Rajat Bhatia: Rajat Bhatia (born 22 October 1979 at Delhi, India), is an Indian cricketer, an allrounder, he has been playing domestic cricket for over 15 years, representing many teams, such as the Tamil Nadu cricket team, his home state, the Delhi cricket team and Delhi Daredevils Kolkata Knight Riders and Rising Pune Supergiants in the IPL.  He was a part of the MRF Pace Foundation when he was young.

Supporting paragraphs: KP: The Autobiography Kevin Pietersen
Answer: David Walsh