Under Isaiah, the Celtics were tough and played with heart and togetherness. Did they lose games or go stretches playing poorly? Yes. But on most nights, they left everything on the court. I don't recall them quitting this badly on such a big stage as last night.
Compared to Isaiah and his teammates, today's Celtics are more talented and are title contenders, but they are mentally weak. There's something in their DNA that's holding them back.