Maybe since you're so good,
he's taking his time to meet the CHALLENGE.
The Big Bang Theory Season 6, Episode 6
I always got stuck on
the first CHALLENGE--
The Big Bang Theory Season 7, Episode 3
Challenge accepted! Sounds like it's time
for the Sheldon Cooper Apology Tour!
The Big Bang Theory Season 9, Episode 13
Ragnar said that
if you refuse his CHALLENGE,
Vikings Season 1, Episode 6
We've accepted the CHALLENGE.
We can't run away from a fight.
The Big Bang Theory Season 2, Episode 12