WALTHAM — Two of the most-respected coaches in the NBA also happen to have the most rings.
But whether the Celtics win another title or not in the next month, Paul Pierce believes he is playing for one of the best coaches of his generation. Pierce said Monday following practice that Rivers deserves credit for keeping the team focused on the task at hand and never showing panic through the course of a long season filled with many ups and downs.
“He’s definitely taken my career to the next level,” Pierce said. “You have to put him up there with the top-five coaches with Phil, Gregg Popovich.”
It wasn’t always that way as Pierce admitted earlier this season when he said his relationship with the Celtics and Rivers was sometimes like when a couple goes through growing pains early in their relationship.
Sometimes you come close to “breaking up” Pierce said but in the end, you work things out.
Such was the case, even this season, when the team went 27-27 to finish the season, losing at home to teams like Washington, New Jersey and Memphis. When the team was battling to find itself in January and February, Pierce said it was Rivers who kept things loose and easy.
“I think it’s everything to this ballclub,” Pierce said . “You can see at times when you play for coaches when things aren’t going right it just seems like the practices get harder and the yelling becomes louder and Doc is a cool customer.
“He didn’t panic, he didn’t get louder. He just stuck with the game plan. A lot of times, when you go through a stretch we went through like five games out of six, seven-out-of-10, you can tell from a coach’s body language that things are going downhill. You never really saw that with Doc. He came in and said, ‘Alight, we’re going to get back to work the next day.’ He always stayed positive and encouraged us and I think that was big for us throughout the year.”
Jackson has an NBA-record 10 titles as head coach while Gregg Popovich is second among active coaches with four. The Celtics are making their second trip to the NBA Finals  in three years with Rivers as the coach and he is trying to join Red Auerbach , Bill Russell  and K.C. Jones as Celtics coaches with two titles in three seasons.