I've been listening to a podcast called "Hardcore History". It's produced by Dan Carlin, and I'm in the middle of his series on the Punic Wars. (The wars between Rome and Carthage.)
Carlin describes the Romans as folks whose greatest asset was their refusal to surrender. They would simply not admit defeat, even when they'd been beaten on the field of battle, and would just keep going until they wore down their enemy.
He quotes a historian who describes it:
Victory through Superior Determination.
Thinking through his soccer career, business career, CrossFit career, and other general moments of his life,
I thought that sounded like a good description of Walter, too.