On this day in 1971, John Snow produced one of those spells that completely changes the mood of a Test match. On an unresponsive Sydney pitch, where fast bowlers were supposed to toil without reward, Snow found a way to make the ball talk. From the moment he began his run-up, Australia’s top order looked uneasy. Using a worn patch with ruthless intelligence, Snow extracted steep, awkward bounce and tore through the batting. Wickets fell in a heap as Australia slumped to 21 for 4, the damage done