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 Bent Larsen wrote, annotating a game that began 1.c4 c5 2.b3 b6, "In symmetrical openings, White has a theoretical advantage, but in many of them it is only theoretical." GM Andrew Soltis wrote in 2008 that he hates playing against the symmetrical Petroff's Defense (1.e4 e5 2.Nf3 Nf6), and accordingly varies with 2.Nc3, the Vienna Game. However, there too he has been unable to find a way to an advantage after the symmetrical 2...Nc6 3.g3 g6 4.Bg2 Bg7, or after 3.Nf3 Nf6 ( to the Four Knights Game) 4.Bb5 Bb4 5.0-0 0-0 6.d3 d6 7.Bg5 Bg4 8.Nd5 Nd4 9.Nxb4 Nxb5,