What are the 9 Sprint Goal Principles to Support Your Scrum Team in Finding It's Groove? In a recent blog post from Stefan Wolpers, he discussed these principles: 

1. Have a Sprint Goal in the first place
2. Avoid the top-down Sprint Goal
3. Avoid output-driven Sprint Goals
4. The pseudo-Sprint Goal
5. Have a reasonable forecast
6. Don’t play safe all the time
7. Avoid a confidential Sprint Goal
8. Have a “flexible” Sprint Goal
9. Deliver the Sprint Goal more often than not

https://medium.com/10-min-briefing-on-startup-tech-news/sprint-goal-principles-age-of-product-com-8a904b66c3cc