Professional foul Professional foul In various sports, a professional foul is a deliberate act of foul play intended to bring about an advantage for the perpetrator's team. Professional fouls are usually committed to prevent an opponent from scoring. In association football, a professional foul involves a defender fouling an attacking player in order to prevent them from scoring, or a handball offence that denied an obvious goal-scoring opportunity. The resulting free kick or penalty may offer the attacking team a lower chance of scoring than the original playing position, and the defending player therefore has an incentive to tactically foul the attacking
First-move advantage in chess better for White, while 1.b3 is playable but less likely to yield an opening advantage than 1.e4 or 1.d4. Watson concludes that Rowson writes that "in general one would assume that whatever advantage White has would be revealed most clearly in symmetrical positions." Accordingly, Watson, Suba, Evans, and the eminent player and theorist Aron Nimzowitsch (1886–1935) have all argued that it is in Black's interest to avoid symmetry. Nonetheless, even symmetrical opening lines sometimes illustrate the tenuous nature of White's advantage, in several respects. It is often difficult for White to prove an advantage in symmetrical opening lines. As GM