Round 5 of the IV Masters Ciudad de Buenos Aires tips off Wednesday night in the Argentine capital. Stopa, Valerga, Rodriguez, Hoffman, Slipak, and Sorin battle it out in this nine-round Swiss affair. The 90-minute time control with 30-second increment gives these players room to think, but not endless time to calculate. Buenos Aires chess circles will watch closely as the field shapes up midway through the tournament.