what do you consider a 'smart' fighter?

[Coco]

Barrera was a smart fighter, he adjusted his style as he got older and slowed down

And actually got better, especially after he got exposed a bit against Junior Jones

[Grilling Machine]

When Usyk disengaged from a cornered Fury and didn't take the bait when Fury played to the crowd with chicken theatrics.

Usyk knew it was too early to hurt him in a shell, and so invited him to reset his reach advantage.