In international T20 cricket as well in T20 leagues bowlers like Lasith Malinga, Rashid Khan, Jasprit Bumrah, Dwayne Bravo, Yuzvendra Chahal, Jofra Archer, Mitchell Starc, Dale Steyn, Imran Tahir and Shahid Afridi have been excellent with the ball. They have won many matches on their own and are regarded best bowlers in the world in this format. And here is the list of most wickets, four-fers and best averages by bowlers in winning causes in T20I cricket. 

Most T20I Wickets in winning causes -

75 - Rashid Khan (Afghanistan, 36 Matches)

67 - Lasith Malinga (Sri Lanka, 41 Matches)

66 - Shahid Afridi (Pakistan, 56 Matches)

59 - Umar Gul (Pakistan, 34 Matches)

53 - Ajantha Mendis (Sri Lanka, 25 Matches)

52 - Mohammad Nabi (Afghanistan,53 Matches)

50 - Dwayne Bravo (West Indies, 37 Matches)

49 - Saeed Ajmal (Pakistan, 35 Matches)

46 - George Dockrell (Ireland, 32 Matches) 

44 - Jasprit Bumrah (India, 34 Matches)

Most four wickets haul in winning causes in T20I cricket -

5 - Rashid Khan (Afghanistan)

5 - Umar Gul (Pakistan)

4 - Imran Tahir (South Africa)

4 - Ajantha Mendis (Sri Lanka)

4 - Shakib Al Hasan (Bangladesh)

3 - Mudassar Bukhari (Netherlands)

3 - Yuzvendra Chahal (India)

3 - Lasith Malinga (Sri Lanka)

3 - Mohammad Nabi (Afghanistan)

3 - Saeed Ajmal (Pakistan)

3 - Shahid Afridi (Pakistan) 

Best bowling averages in winning causes in T20I cricket -

9.94 - Ajantha Mendis (Sri Lanka, 53 wickets)

10.22 - Bilal Khan (Oman, 31 wickets)

10.56 - Rashid Khan (Afghanistan, 75 wickets)

10.60 - Kuldeep Yadav (India, 33 wickets)

11.26 - Imran Tahir (South Africa, 41 wickets)

11.66 - Umar Gul (Pakistan, 59 wickets)

12.84 - Mudassar Bukhari (Netherlands, 33 wickets)

13.65 - Nathan McCullum (New Zealand, 41 wickets)

13.94 - Mustafizur Rahman (Bangladesh, 37 wickets)

13.95 - Lasith Malinga (Sri Lanka, 67 wickets)