A strong draw is defined as a hand with 8 and more outs (for a strong hand) and no showdown value.

 

 

I have a strong draw, with 8 or more outs, in the following situations:

 - I have a straight draw with 2 cards in my hand in a rainbow non paired table*

 - I have a flush draw with 2 cards in my hand in a non paired table.

 - I have a flush draw with one  or in my hand in a non paired table.

 

*Excluding the bottom end straight draw, also called the idiot end.