In defense of Celtics point guard Isaiah Thomas' All-Star bid

The Boston Celtics are in Toronto on Wednesday to meet the Raptors and, if Isaiah Thomas has his way, he'll sacrifice a bit of his February vacation in order to trek back there for the 2016 All-Star Game.

There is little reason to belabor Thomas' All-Star case based on his offensive numbers. The 5-foot-9 point guard is averaging career bests at 21.8 points and 6.6 assists per game. The only other players in the league averaging 21-plus points and six-plus assists are former All-Stars in Stephen Curry, James Harden, LeBron James, Damian Lillard, Russell Westbrook, and Kyle Lowry. Thomas has almost single-handedly kept Boston's offense afloat at times this season as evidenced by the fact that Boston owns an offensive rating of 104.9 when he's on the floor, while that plummets to 94.8 when he's on the bench -- a difference of 10.1 points per 100 possessions.

But in stumping for Thomas recently, it's been interesting to hear Celtics coach Brad Stevens cite his defense as a possible reason for his inclusion.

"[All-Star] spots are earned, and [Thomas] sure has done a lot of work," Stevens told reporters in Dallas on Monday night. "He’s not only a dynamic scorer, but the way that he’s able to run the offense, the way that he’s been able to defend for us, just his all-around game, I think, obviously, he’s elevated our team."

Boston ranks second in the NBA in defensive rating by allowing 98.8 points per 100 possessions, but it's often assumed that they sit there in spite of Thomas. Boston's roster is heavy of defensive-minded players and there's a notion that they help mask Thomas' deficiencies.

But Stevens has said repeatedly that Thomas has improved as a defender since his arrival last February and believes that reflects on his overall impact on Boston's team success. Stevens' comments sent us scrambling to Synergy Sports to watch clips of Thomas' defense and examine his defensive progress.

What you find is a player who has been put in positions to limit his ability to be exploited and is certainly aided by the talent around him, but Thomas' individual numbers suggest there has been improvement. If nothing else, there's an obvious desire to be competitive on that side of the ball.

According to Synergy Sports' grading, Thomas is allowing 0.759 points per play defended, which is the second-best number on the team behind only Evan Turner (0.726 PPP) and ranks in the 89th percentile among all defenders. Narrow the field to all defenders with at least 300 plays defended and Thomas ranks 12th in the league, one spot behind -- are you sitting down? -- 2015 defensive player of the year Kawhi Leonard.

Let's throw some cold water on this. Synergy's defensive data can be slightly misleading. For example: If a guard blows past Thomas on the perimeter and finishes over Amir Johnson near the basket, it's more likely that Johnson will be credited with being scored upon, even though he's simply scrambling to help a beaten teammate.

So we checked the league's player-tracking data, which uses cameras above the court to better analyze defensive impact. Through 40 games, Thomas is credited with limiting his opponents to 42.8 percent shooting, which is still a positive number considering that's 0.8 percent below those players' season average (43.6 percent).

The player-tracking data also shows that Thomas is limiting opponents to 24.7 percent shooting from beyond the 3-point arc, or a healthy 10.3 percent below those players' season average (35 percent). It won't come as any surprise that, as Thomas' defenders get closer to the basket, their shooting percentage rises (with opponents shooting a robust 73.8 percent inside of 6 feet, or 15 percent higher than their averages).

In an effort to limit how often teams are able to exploit Thomas, the Celtics have often put him on perimeter shooters, like on Monday night when he guarded the Mavs' Chandler Parsons to prevent point guard Deron Williams from trying to maximize a size advantage.

No one is going to suggest that Thomas has transformed himself into a defensive stopper. But on a team that's switch-happy, he's embraced being the one guy that must fight through screens to stay with ball handlers. And he uses his quickness to help while sinking in, then racing out to contest 3-point shots.

Thomas still owns the worst defensive rating on the Celtics, among regulars, at 100.8, but that's a rating that would rank a team near the top 10 in the NBA (the Raptors have a defensive rating of 100.8 and currently sit 11th). Boston's defensive rating sits at 94.7 when Thomas is not on the floor, the lowest among all players on the team, which is a reflection of both a bench that has been excellent and the defensive uptick that occurs when Boston has players like Marcus Smart and Turner as part of those switch-happy second units.

To Stevens, the bottom line is progress. Thomas arrived with a reputation as an undersized defensive liability and has bought into Stevens' requirement that his players make defense a priority. In 64 games between Phoenix and Boston last season, Thomas owned a defensive rating of 104.5. His three seasons in Sacramento featured defensive ratings of 104.8, 107.4, and 107.6.

Ultimately, it's Thomas' offensive exploits that will determine whether he receives his first All-Star bid. It's fair to wonder just how cringe-worthy Boston's offensive efficiency would be without him (the Celtics rank 19th in the league with an offensive rating of 101.7). Not only is Thomas' scoring and playmaking important, but he's one of the few on the team that can create for himself off the dribble and get to the free throw line with any regularity.

The NBA will announce All-Star starters on Thursday. Thomas, after lingering ninth in the fan vote through three returns, will be at the mercy of the Eastern Conference coaches to vote him on as a reserve (that announcement will come on Jan. 28). Thomas should hope that Lowry made a late surge to overtake Kyrie Irving as a fan-voted starter, because that might strengthen his chances of sneaking in as one of the East's wild-card picks. Irving has played just 13 games this season and wouldn't be selected by the coaches.

As Stevens told reporters Monday: "There’s a lot of good players in the league, I understand that. I don’t know that they’re all as impactful on their teams as Isaiah is on ours."