If

After Philip II of Macedon had successfully united most of Greece through a combination of military might and diplomacy, he turned his attention to Sparta, the one major city-state that remained unconquered. Knowing the Spartans’ reputation for bravery and their commitment to independence, Philip sent them a threatening message: “You are advised to submit without delay, for if I bring my army on your land, I will destroy your farms, slay your people, and raze your city.”

The Spartans’ reply set a new standard for tough talk; they sent back a single word: “If.”

Competitive sport athletes also often engage in mental games, trying to unnerve opponents before a matchup, which is well within their right: no sport has rules against “intense eye contact” or “showcasing confidence,” so it only makes sense to try to create a little psychological advantage before the competition begins.

In his seminal work, The Inner Game of Tennis, Timothy Gallwey describes a subtle yet powerful psychological tactic that exemplifies this kind of strategy. He notes how merely complimenting an opponent’s technique after a series of exceptionally well-placed serves can paradoxically lead to a decline in their performance. The psychology behind this is fascinating: drawing conscious attention to what was previously an unconscious, fluid motion increases self-awareness, which leads to overthinking, an eventual breakdown in natural rhythm, and—a performance decline.