show (your) mettle

See at: prove mettle

• battle of nerves
• battle of the sexes
• battle of wills
• battle of wits
• be a athlete in the making
• be a [athlete/star/writer etc.] in the making
• be a barrel of laughs
• be a bed of nails
• be a bit much
• be a blessing in disguise
• be above board
• be a bundle of laughs
• be a bundle of nerves
• be a chapter of accidents
• be a closed book
• be a [crisis/disaster etc.] in the making
• be a crisis in the making
• be a crock of shit
• be a cut above
• be a cut above someone
• be a cut above something
• be a dab hand
• be a dead cert
• be a dead loss
• be a dead ringer for