Terry brings multiple attributes the Celtics need.
A boisterous, ballsy, born baller, Terry signed a three-year, $15 million deal with the Celts on the Fourth of July, ending a nine-season run with the Dallas Mavericks that included a Sixth Man of the Year award in 2009 and an NBA championship in 2011.
When Allen signed with the Miami Heat just two days later, that made it official. Terry would be the Celtics' new, veteran scorer/long-range shooter/sparkplug. But the biggest difference between the two of them was Allen did not want to come off the bench in Boston (even though he'll be doing just that in Miami), while Terry welcomes that role.
Terry was primarily a starter in his first three seasons as a Mav after spending the majority of his five years with the Atlanta Hawks, his first NBA team, in that role as well. But in 2007-2008, Terry went from starting 80 games the previous season to just 34.
He would go on to start just 34 of 296 games his next four years in Dallas.
Terry thrived coming off the bench, scoring at least 15 points per game in each of his last five seasons—including a high of 19.6 in 2008-2009. Not coincidentally, that was the year he won the Sixth Man of the Year award.
Terry is instant offense. He's not afraid to shoot the ball, whether it's from deep or mid range. For a player who relies primarily on shooting jumpers, his career field-goal percentage is 45 percent. That's pretty good.
Then there's the skill Terry possesses better than Allen does: the ability to play the point. The Celtics didn't sign a back-up point guard for Rajon Rondo because they already have one in Terry.
At 6'2", Terry is not anywhere near your prototypical shooting guard, which is why his ball-handling and distribution skills come in so handy. Over the course of his career he's averaged 4.7 assists per game.
So, while the Celtics will be counting on Terry to score off the bench, they can be secure in knowing that he's a pretty good point guard, too.
In the end, given the Celtics' overall youth in the backcourt (Rondo, Avery Bradley, Courtney Lee), the departure of Allen's scoring punch and the their lack of a true, back-up point guard, Terry's presence on this roster is a major boost. His skill set across the board, along his willingness and ability to succeed coming off the bench, is key.
If those factors don't add up to an ideal addition for the Celtics, what does?