You conveniently left the next part out "A stretch four is a player that is of power forward size but has superior shooting skills (especially three-point field goals), spending more of their time away from the basket'."In basketball, a stretch four is a player at the power forward position that can generate offense farther from the basket than a conventional power forward. "Stretch" describes the effect such a player has on the opposition defense, and the power forward position is also known as the "four"; hence "stretch four".
Nothing about 3-point shooting, just "farther" from the basket.
But it's cool that you had to google it