Cleggett knew that sooner or later a winded man makes a fault.

The lungs labor and fail to give the blood all the oxygen it needs.

The circulation suffers.

Nerves and muscles are no longer the perfect servants of the brain; for a fraction of a second the sword deviates from the proper line.
It was for this that Cleggett waited, pressing Loge closer and closer, alert for the instant when Loge would fence wide; waxing as the other waned; menacing eyes, throat, and heart with a point that leaped and dazzled; and at the same time inclosing himself within a rampart of steel which Loge found it more and more hopeless to attempt to penetrate.

It was as if Cleggett's blade were an extension of his will; he and his sword were not two things, but one.