There are a few principles that I follow.
- 12-13 points, including distribution, to open at the 1-level in first or second seat. I count 11 here.
- When preempting be within 2 tricks of the contract at unfavorable vulnerability, 3 at equal, 4 at favorable. I value this hand at 6-7 tricks.
- I like to bid and am reluctant to allow that a hand is too good to preempt but not good enough for a 1-bid.