Childress, 25, is the first player at this stage of his NBA career to spurn the world's most high-profile basketball stage for one of its international alternatives.
Atlanta had offered him a five-year, $33 million contract. But the Hawks' slow-paced negotiating tactics and the limits of restricted free agency, combined with what Childress called Wednesday the "opportunity of a lifetime," resulted in his decision.
Whether others follow remains to be seen, but Pandora's Box has clearly been opened.
"I've talked with a few guys and it could become a trend," said Childress, whose net pay from Olympiakos will be $20 million. "I'm not so sure it won't. It's certainly different. We thought outside the box on this one. If players can see a fellow NBA athlete come overseas and live a normal life and adjust to the culture [they may] think, why not me? I'm also interested to see how these next weeks turn out for some of the other restricted free agents in my draft class."