Best American ever, who knows, but I do think the Rio 1500 was the most impressive race ever run by an American. OP did a good job of laying out how good the field was, and others have talked about Centro's various strategic coups within that 3 minutes 50 seconds that allowed him to put the favorites out of position at key points in the race. I keep going back to that race time and again and each time I spot something new that Centro did or caused to happen that led to his victory. The biggest key for me was being the one to ramp up the pace, and to do it earlier than the favorites wanted (with 700 to go). The New Zealand commentary, which you can find on Youtube, is especially great because the two announcers really pick up on all the movement that's happening and on the third lap they notice that both Kiprop and Makhloufi are in terrible spots and have a lot of work to do to get back in the race. All thanks to the size of Centro's balls, really, as a certain Australian runner might have said. Kiprop having to make a second move killed him for the final sprint, and Makhloufi having to go around Kiprop's corpse helped Centro hold the defending champ off, and he needed it because Mahk was closing very fast indeed. Brilliant all around.