We are approaching that wonderful time of year when advanced stats and analysis become most useful. The sample size is large enough to show patterns, but the patterns don’t have to hold for the rest of the season because there are still so many games left. So no stats-heavy article written at this time of year should be calling for drastic changes and overhauls (unless that article is about the Wizards because yeeeeeeesh),but they CAN point out disturbing trends that need attention.The Celtics have played 11 games so far this year, and one of the biggest non-defense related problems has been Courtney Lee’s lack of consistent production off the bench. When Lee signed with the Celtics, he was considered a steal, an infusion of athleticism, youth, talent and energy entering the game with the second unit. Boston’s bench was severely unproductive last year, so Lee was hotly anticipated as a contributor.But Lee hasn’t produced like we hoped. In fact, Lee has produced like members of last year’s bench. Excluding the interchangeable Ray Allen/Avery Bradley duo who traded starting spots/sixth man roles, the bench player with the most minutes played was Mickael Pietrus. PER TS% 3-Point % Corner 3 %Mickael Pietrus8.50.5070.33542%Courtney Lee7.60.5200.22227%So we are actually seeing LESS production from Courtney Lee than we did from Mickael Pietrus last year, which is a bad sign since Pietrus’ 8.5 PER put him at just better than half the league average of 15.0. Not good times.Lee was supposed to put an end to that. He was never a superstar of efficient production, but that’s the risk you run when you are a jumpshooting guard like Lee. Players who shoot from distance miss more shots inherently and thus are less likely to show up as hyper-efficient in the advanced stats. So Lee’s 12.6 PER last year was explainable and acceptable. His 7.6 PER this season is far from.What’s interesting about Lee’s problems is that he’s actually averaging his highest field goal percentage of his career at .455. Certainly, he’s benefitting from a small sample size (just 258 shots so far), but it’s been quite evident to anyone who watches the team on a nightly basis that Lee has been struggling. He has been consistently utilized in just two different offensive plays so far this season: spot-up shots and transition attempts. Where is he struggling the most?The answer is easy: spot-up opportunities, by a pretty wide margin. In transition, Lee has been mostly what we were hoping for. He’s averaging 1 point per possession, per Synergy Sports, and he’s shooting just over 50%, which is perfectly acceptable.But in spot-up opportunities, Lee has been much less effective. He is averaging just 0.67 ppp on 21 opportunities, and he’s 2-13 from 3-point range for a disturbing 15.4%.Last year Lee was fairly mediocre from mid-range (39% per the NBA Stats Cube) and very good on corner 3s (49%). This year, those numbers are reversed. Lee is shooting 57% from mid-range and 29% from the corner. So why is Lee struggling so much in an area from which he was fairly decent last year? Take a look at some field goal attempts from Lee this season.These shots are fairly indicative of most of Lee’s field goal attempts. Boston has a lot of offensive threats, so with the defense focused on Rondo/Garnett/Pierce, Lee often finds himself with a very clean look at the hoop. There doesn’t appear to be anything fundamentally wrong with his jumper. He’s not very contested. The passes are catching him in rhythm. To put it as bluntly as possible, he’s just missing shots.This is both good and bad. Clearly, it’s bad that Lee has started the season off his game. But since nothing seems to be wrong with his shot and since Boston’s offense continues to give him clean looks, it seems likely that he will progress to the mean, making him a much more viable spot-up threat. Lee is averaging nearly three shots fewer per 36 minutes than any other season of his career, including his rookie year. He’s also averaging nearly seven minutes per game fewer this year than last year. So it’s eminently possible that Lee is actually just struggling adjusting to his new role and that once he adjusts, he will start making more of his shots.Boston is 7th in the NBA in spot-up opportunities at 1.03 ppp, so Lee’s struggles aren’t the paramount problem for the C’s. That dubious award would go to the struggling defense and the godawful defensive rebounding. But if Courtney Lee can find his shot, expect the offense, which is already scoring four more points per 100 possessions than it did last year, to get yet another shot in the arm.Follow Tom on Twitter: @Tom_NBA.