Step up to the plate
Definition 1 of 2
Pro Tip 1/3Metaphoric Use
Used metaphorically to mean accepting a challenge, not just in baseball. 
After our project leader left, Lisa really stepped up to the plate.
Pro Tip 2/3Initiative Highlight
Emphasizes the person's willingness to act without being asked. 
With the community in need, volunteers stepped up to the plate to help.
Pro Tip 3/3Leadership Signal
Suggests a person is taking a leadership role in a difficult situation. 
During the crisis, the young senator stepped up to the plate.