There is literally a 0% chance the C's bring Brandon Bass back, unless they plan on tanking cuz he does hold value if you want to do that! The disaster that is him is finally over. He never added anything at anytime. People are amazingly still fooled by players that can jump high, play a little on ball defense, and make mid range jumpers. He is a terrible help defender, cannot stretch the floor, is a poor rebounder, is one of the worst rim protectors in the league, cant pass and cant run offensive sets through him. He has posted the worst plus-minus numbers 3 years running and people on this forum inexplicably think that he still holds value. The truth is he holds no value to a contender or any other team that is trying to win games. The clippers will pick him up though Doc has no clue about analytics.
Bass is the most versatile defensive big we have right now - he's capable of defending positions 3 through 5 competently.
There is nobody else on our roster bar maybe Jerebko who can do that.
Bass has also been one of the best midrange shooters in the league for about 5 years running. He's good enough at it that opposing teams always need to be aware of where he is - makes it hard for teams to double inside because leaving bass in the 15 foot range is an almost certain two points.
On midrange jumpers (between 10" - 3PT) Bass has shot 46% for his career - up there with some of the best percentages ever by a big.
He's also very good at getting points from the line. For his career he's shot 82.8% from the foul line, and has a career Free Throw Rate of 32.5%, which is a good number and is a skill the Celtics are in dire need of as you can see by looking at the career numbers of our other PFs:
Jared Sullinger: 21.6% FTR / 76.2% FT
Kelly Olynyk: 25.8% FTR / 74.4% FT
Jonas Jerebko: 26.2% FTR / 76.4%
He also has a spectacularly low turnover rate (10.9% for his career, 9.6% last season). If you look the NBA all time leaders in turnover rates, you will appreciate how like a rate of 9.6% actually is - it's up around top 10 all time.
This is unfortunately offset by the fact that he has all of about zero passing ability. Not only is he not a GOOD passer, but he's also not a very WILLING passer. In the big 3 era he was the pure definition of a black hole on offense - once the ball got in his hands, it was guaranteed he was going to shoot it. Hence the "no-pass Bass" nickname. However i have to say he's improved a LOT with this over the years, and there is no denying that he's a more willing passer now than he was back then. The numbers back this too since his assist numbers have nearly doubled (from 1.1 AST Per 36 in 2011/12 to 1.9 AST Per 36 in 2014/15) while his turnovers went up only slightly (from 1.3 TO Per 36 in 2011/12 to 1.5 TO Per 36 in 2014/15). That means his assist/turnover rate has increased from 0.84 in 2011/12 to 1.26 in 2014/15 - a modest improvement on paper, but very noticeable in person.
Bass still is not a good passer by any means, but he's become a lot better at recognizing when he has a good offensive opportunity, and making the right decision on whether to shoot the ball or pass to a teammate.
He's also improved a lot as an inside scorer. In the early big 3 era, Bass had zero ability to score inside. He would get in the paint, catch the ball, come down with it, attempt two slow motion pump fakes (which did nothing but allowing the opponent time to get set) and then would go straight up...and get blocked. He would drive past defenders, but could never finish. He's dramatically improved, and is now a pretty good finisher inside - even if he's still pretty lacking in post moves. An indication of how much he's improved? In 2011/12, his first season with Boston, he shot 55.3% on attempts inside three feet. In 2014/15 he shot 68% inside three feet - that's an elite number and up there with the best in the league. A very impressive number given that he only stands 6'7" with shoes.
For his career bass has averaged 7.5 Rebounds Per 36 Minutes - that's not a fantastic number by any stretch of the imagination, but it's not terrible. I'd say the average is probably around 8 per game for a PF, so Bass would be pretty close to average / slightly below average.
Defensively he has his strengths and weaknesses. The plus is that he has decent physical attributes (strength, mobility, length) and that gives his the ability to play solid on-ball defense at the SF, PF and C spot. This also helps his P&R defense, because he has the ability to switch onto quicker wing players (like Lebron, Carmelo, etc) or bigger interior players (like Demarcus Cousins) and at the very least hold his own against them defensively. He also has a very high motor - plays hard ALL THE TIME and never gives up on plays or loses by lack of effort.
Unfortunately his defensive IQ is not that high though, so he's not the worlds greatest help defender - often finds himself in the wrong spots defensively, etc. As a result his team defense is not up to par with his individual defense. But he can still hold his own against his assignment more often than not, which is more than I can say for some guys (e.g. Sully) on the roster.
Although he's not that young anymore, nor that physically talented, Bass has surprised everybody by showing significant (and consistent) improvement year by year. Every year he's improves some part of his game - given his lack of outright talent, that's purel a sign of his outstanding work ethic. I would hazard a guess that this off season, he'll be working on his three point shot...and if he can add that skill set to his game (the ability to it the three at a 34% - 36% rate) his value will jump exponentially.
Bass is certainly 'limited' as a player, it's obvious that he's never going to be a star. He also has clear limitations (BBIQ being the main one). But he is a great locker room guy, he's incredibly constent game to game. You can always depend on him to come into every new season in top physical shape, and you can always depend on him to bring great effort, professionalism, and hustle ever time he steps on the court.
If we can sign him for a modest sum (maybe $5M-$6M a year) then IMHo he is well worth that as veteran leader and glue guy who can come off the bench to provide solid minutes at both forward spots...especially considering the upcoming cap rise, and the fact that we may lose Sully after this year (he's going in to his last year of his contract).
To be honest I would rather move forward with Olynyk + Bass than I would with Olynyk + Sully. Sully is just too much of a liability on both defense (with his lack of mobility and versatility) and offense (with his obsession with spot up jumpers and complete lack of interest in getting to the basket). Throw in the fact that he's going to be a FA in a year (and likely will wan top money) and he is (to me) the top of the list of guys likely to get traded by the deadline.