Model takes chance regularly for good ability to get results (8)

I believe the answer is:

efficacy

'ability to get results' is the definition.

I cannot understand how the rest of the clue works.

(Other definitions for efficacy that I've seen before include "Being able to work" , "Force" , "The ability to produce a desired or intended result" , "Ability to produce required result" , "Effectiveness" .)

I've seen this clue in The Times.

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