The New York Times runs an election tracker web page that calculates the odds of presidential victory, popular vote margins, and projected Electoral College totals, in addition to monitoring the final state-by-state results.
At the beginning of Election Eve, the tracker gave Hillary Clinton an 85% to win the election. Within two hours, the odds had shifted to a 50-50 race. At 10:30 PM Eastern time, with the last few decisive swing states waiting to be called, the odds stood at 90% for Trump.
It was an amazing ride for the election tracker, raising some interesting questions about how the odds were calculated, and what data the Times was feeding into its system in advance of the formal state calls.