### Comment:
Ah, your post made it sound like you wanted to avoid assignment.  
  
 To calculate the expected move, take the short straddle price (selling an ATM put and ATM call) and multiply it by .85. In this case the short straddle price for GOOG at Feb 8 exp was $50.95, times .85 gives us an expected move of +/- $43.30, putting your short put just inside the bottom of the expected move.

### REPLY:
why 0.85?

### END.