Okay some interesting stuff here when digging up some facts.
Celtics avg 90 shots per game last year. Kemba Avg 20.5 shots per game last year which in my opinion needs to go down.
The success of the Celtics is going to be in large part up to Kemba Walker and how he adapts to playing with much better teammates.
He averaged 25.6 points per game last year on .434 percent from the field. Career .418% shooter. Not good, in his defense he's been playing on a very poor team with poor players.
Using FG% isn't really the right tool for looking at this. A player shooting 39% but who took nothing but threes would be a very efficient scorer but a player hitting 46% while taking nothing but 2PT jumpers (and never getting to the FT line) would be an inefficient scorer. And a third guy, hitting 46% on nothing but 2PT shots but who also got to the FT line on a third of his scoring attempts would be a very efficient scorer.
What you want to look at is
scoring efficiency -- how efficiently a player converts
scoring attempts into points.
And remember, FGA does not include all scoring attempts. If a player drives to the hoop and gets fouled, missing the layup but getting two free throws, no FGA is counted. But that IS a 'scoring attempt'.
The Celtics averaged 99.08 'true scoring attempts' per game last year. That resulted in 90.5 FGA and 19.5 FTA per game. But that was with some high-usage scorers who seem unable to draw fouls and get to the FT line. Kyrie, Al, Tatum, Morris, Smart -- these guys took a ton of our shots but were terrible at getting to the FT line -- none had an FTA/FGA ratio above 22.8%. Kyrie and Al were both _below_ 20%!
This year's scoring should involve a lot more usage by scorers such as Kemba, Gordon, Jaylen and Kanter -- all guys who have much higher FTA/FGA ratios. In fact all of those 4 guys have posted FTA/FGA ratios well over 25% every year and most have typically been close to 30%. Add in the possibility of rookies Romeo, Grant and Vincent (who all have histories of getting to the FT line) getting any sort of usage and overall our FT attempts should be significantly higher this year than last year.
Based on his getting to the FT line 5.5 times per game, Kemba averaged about 23
true scoring attempts per game. And he converted those into points at a very nice 55.8% TS% (true scoring efficiency). He has posted TS% rates between 55.4% and 57.2% consistency over the last 4 seasons. So he is a well above average efficiency scorer.
It should be noted that both Isaiah and Kyrie similarly averaged TS% numbers in that range in the seasons before they came to Boston --- and then both posted even higher efficiencies in Brad's pick & roll heavy system. So there is reason to expect that Kemba might be even more efficient in Brad's system as well.
Because he gets to the line at a decent rate (his FTA/FGA ratio has been right around 29% for most of his career) that results in pretty consistent scoring efficiency (as opposed to guys who rely solely on shot efficiency). So I'm personally totally fine with Kemba continuing to take 20+ true scoring attempts per game. That should form the main engine for the offense.
I would also like to see Gordon Hayward take close to that. He is also, historically and pretty much again from January onward, an extremely efficient scorer who can score from all levels, including by getting to the line a lot.
I'd like to see Jaylen and Jayson each at somewhere around 17 scoring attempts per game.
I expect Kanter, assuming he plays around 25 mpg, to get his typical ~12-13 scoring attempts per game with around a 3rd of those coming off offensive rebounds -- I.E., not necessarily from running plays. Cleaning up the scoring attempts by others.
Assuming health and nothing weird happening, I fully expect those 5 players to be our most efficient scorers under the heaviest usage. All five of those guys should be north of 55% TS% and so I want the vast bulk of our shots to be taken by them. We'll probably get high efficiency on selective shooting out of a few other players, but I don't expect any other players to get the same heavy usage that those guys should get.
Smart may or may not be able to reproduce the efficiency he shot at last year. It was a big leap upward from prior season. But I personally attest a lot of that to a real mechanical fix he made to his shooting form in the summer of 2017 finally paying off. So he should at least be decent even with some regression. I expect him to be on the floor at least 25 minutes so he's still likely to end up with around 8-ish scoring attempts per game.
Outside of those 6 guys, the rest of the roster should be guys getting less than 8 scoring attempts per game. I can see Carson getting a lot for a rookie, given his expected role as a gunner. Once Romeo is ready, he might get a lot of usage off the bench as well, though I expect him to at least start the year in Maine just to get minutes and rebuild his game after all that rehab.
So, to summarize, I'd like to see (per game, with a little over 105 TSA/game):
Kemba & Gordon: around 20 TSA each
Jaylen & Jayson: around 17 TSA each
Kanter: around 12-13 TSA
Smart: around 8 TSA
Everyone else: under 8 TSA each
Keep in mind that not everyone will play every game, especially bench players.
If we get that kind of shot distribution, and guys are able to deliver their expected scoring efficiencies, then our offense should be pretty potent.