1.   Why did this tactic work so successfully?

2.   The fast bowling tactic has worked.

3.   And he thinks the tactic has worked.

4.   And in every one of those cases, the tactic worked.

5.   And the tactic worked.

6.   And they are negative because that tactic works.

7.   But his tactic apparently worked.

8.   But occasionally, the tactic has worked.

9.   But that tactic can only work in the short term.