Professional foul stop the clock and get the ball back, rather than allow the opponent to run out the clock. In addition, there are specific rules governing obvious goal scoring opportunities called clear path fouls. The professional foul in rugby league embodies a similar concept to other sports, a deliberate breach of the rules in order to prevent a scoring opportunity. The penalty for this offence is 10 minutes in the sin bin. The majority of professional fouls are either holding down the tackled player after a break has been made in order to allow his teammates to reform in defence, interfering
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