All that juice the Pistons generated from the Blake Griffin trade? Vaporized, swept away by waves of defensive lethargy. Barely a week after they made a bold move to save their season, the Pistons have reverted in alarming fashion. From a spark to a fizzle, the Pistons have lost three straight, surrendering meekly to New Orleans, 118-103, on Monday night at Little Caesars Arena. This was an embarrassing effort, one night after another embarrassing effort in a 118-115 loss at Atlanta. After winning five straight, there was some concern the Pistons were standing around on offense, watching Griffin operate. Not the problem here. They simply stood around on defense and watched the Pelicans operate, and when superstar Anthony Davis (38 points) has room, he uses it and abuses it. Stan Van Gundy was perplexed. So were Andre Drummond and Griffin. You could call it inexplicable, except that this team bounces up and down so wildly, it’s impossible to know what’s next. It definitely was inexcusable, as the Pistons wadded up the goodwill from the Griffin deal and tossed it aside. Just when they started grabbing long-sought attention, they dropped this hideous bomb. This one stung them deeply, and there was some serious introspection afterward. “Those effort plays we haven’t been making, loose balls on the ground, nobody’s been diving for them,” Drummond said. “Maybe we got ahead of ourselves, excited about the five wins. Maybe people are banged up, maybe people are tired, could be a list of things. But I think it’s inexcusable for our play defensively.”