By Chris Mannix,Howard Beck ECF predictions leading into Game 5. Chris Mannix and Howard Beck break down an ugly Eastern Conference finals that has been back and forth, and why Jayson Tatum is the key to the Celtics winning the series. The following transcript is an excerpt from The Crossover NBA podcast. Listen to the full episode on podcast players everywhere or on SI.com. Chris Mannix: All right, so let’s talk about the Eastern Conference playoffs, which is really the only series with any kind of drama at the moment. Tied up at two, going into Game 5 on Wednesday. I wrote about this over at…