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A perfect example of a bio-inspired aerodynamic application in sports was the use of small longitudinal grooves("riblets")on the hulls underside surface of "Stars and Stripes," the Americas Cup winning boat in 1987.This riblet design,which was inspired by the skin surface on fast swimming sharks,resulted in lower drag on the boat.The shape and flexibility of fish fins have also inspired new designs for swimming and diving fins.The use of bionic limbs in sports can have huge implications.The "blade runner" story of Oscar Pistorius who used carbon-fiber prosthetic legs in the 2012 Olympic Games is well known.There was a lot of discussion and controversy over how much of an advantage he gained by using these artificial legs.What if an athlete has a limb bionically altered(in a subtle way)so that he/she gets an advantage in terms of performance(speed or mobility)? Aerodynamics plays a prominent role in defining the flight of a ball that is struck or thrown through the air in almost all ball sports.The main interest is in the fact that the ball can often deviate from its initial straight path,resulting in a curved,or sometimes an unpredictable,flight path.Lateral deflection in flight,commonly known as swing,swerve or curve,is well recognized in many sports,including soccer,tennis,baseball and cricket.In most situations,the lateral deflection is produced by spinning the ball about an axis perpendicular to the line of flight,which gives rise to what is commonly known as the Magnus effect.A side force,which makes a ball curve through the air,can also be generated in the absence of the Magnus effect.In particular,there is an interesting variation whereby the ball is released or kicked with minimal spin imparted to it.