这句是下段<The Man in the Arena>的其中两句，在下用[]记下了
It is not the critic who counts; not the man who points out how the
strong man stumbles, or where the doer of deeds could have done them
better. The credit belongs to [the man who is actually in the arena,
whose face is marred by dust and sweat and blood;] who strives valiantly;
who errs, who comes short again and again, because there is no effort
without error and shortcoming; but who does actually strive to do the
deeds; who knows great enthusiasms, the great devotions; who spends
himself in a worthy cause; who at the best knows in the end the triumph
of high achievement, [and who at the worst, if he fails, at least fails
while daring greatly], so that his place shall never be with those cold
and timid souls who neither know victory nor defeat.
Theodore Roosevelt

句子重组後大概是这个样子:

The man who is actually in the arena,
whose face is marred by dust and sweat and blood; and who at the worst, if he fails, at least fails
while daring greatly.