The case as presented here: A CRICKETING VIEW: The Greatest Match Winner Of All Time
Dale Steyn took his 350th Test wicket in his 69th Test at Kingsmead, Durban against India on December 30, 2013. His strike rate over 350 Tests is unmatched - 42 balls per wicket. Richard Hadlee, the other fast bowler who reached his 350th wicket in his 69th Test, at 50.8 balls per wicket. Dennis Lillee had 347 wickets after his 69th Test. Waqar Younis, whose strike rate almost matches Steyn's, had 315 wickets.
But it is in wins that Steyn sets himself apart from his foremost equals among fast bowlers. South Africa have won more than half the Tests Steyn has played in. Steyn has 247 wickets in those 37 wins. Richard Hadlee comes close in the 22 Tests that New Zealand won when he played.
Statistically, Steyn is the greatest match winner of all time in my view. He hasn't had a steady partner at the other end. Vernon Philander's arrival has certainly helped. Morne Morkel has shared 26 Test wins with Steyn, in which the former has 96 wickets. In wins, Steyn's wickets have come at 16 apiece. But it is his strike rate which sets him apart from his peers - a wicket every 5 overs. No other fast bowler has more five wicket hauls in wins. The three spinners Muralitharan, Warne and Kumble have more, but their wickets have taken longer to come. If we exclude the minnows (Bangladesh and Zimbabwe), then a large chunk of Murali's 5 wickets hauls in wins (41!) are eliminated. He has a humane 24 five wicket hauls in 33 wins. But Steyn's record is undiminished. He still has 225 wickets in 33 wins at the rate of one wicket every 31.2 balls.