"How could Xerxes have lost to the Greeks when he had such overwhelming organization, logistical expertise and numbers of soldiers?".
King Xerxes lost to the Greeks due to his overwhelming confidence that sheer numbers and logistical preparation would prevail. The decision to invade Greece was some what influenced by his late father's wish to defeat the Greeks. His father previously failed twice in his attempts to punish the great city-state of Athens and had planned for a third expedition but due to his death Xerxes must have felt "obliged to carry out his father's plans, to punish Athens for the burning of Sardis and to avenge the Persian defeat at Marathon." (Cameron from Studies in Ancient Persia pg 115). He had to restore Persian prestige after what Athens had done. This expedition would be the largest against the Greeks with an enormous amount if time preparing logistically with roads, canals and bridges to help the massive army and navy that would lead the onslaught onto Greece. However the Greeks used their tactical supremacy over the Persians by deciding intelligent battle plans and battle landscapes to suit their strengths. Their weaponry was far more advanced and their troops had superior training. Xerxes choice to ignore the Greeks strengths led to the failure of the campaign to Greece.