It's easy to forget now, but there was a time in late November when Boston Celtics guard Marcus Smart struggled so mightily at the free throw line that the Miami Heat employed a Hack-a-Smart strategy with hopes of crawling back into a game between the two teams.

Smart shot a meager 58.1 percent (18 of 31) through the first month of the NBA season, which makes it all the more remarkable that he is now shooting 80.2 percent from the free throw line this season.

Twice in the final 24 seconds of Friday's win over the Brooklyn Nets, Smart calmly made a pair of free throws to help the Isaiah Thomas-less Celtics escape with a 98-95 triumph at the Barclays Center.

Since the start of December, Smart has connected on 84.1 percent of his free throw attempts (148 of 176), a mark that would rank him among the top 40 free throw shooters in the league if maintained.

Marcus Smart was clutch at the free-throw line in the closing moments of Friday's win over the Nets. Isaiah J. Downing/USA Today Sports

Smart shot 64.6 percent at the charity stripe his rookie season before improving to 77.7 percent last year. As his free throw attempts climb, the continued rise in his percentage is an encouraging sign for a player whose shooting woes are constantly referenced.

It makes you wonder if Smart can find something in his free throw progress that might help him find more efficiency with his overall shooting. While those within the Celtics organization recognize the way that Smart's defense and playmaking have played a key role in putting Boston in position to make a run at the No. 1 seed in the conference this season, the national view of Smart tends to harp on his offensive inefficiencies.

Smart is shooting just 37 percent from the floor this season -- and that's a career high. Among the 355 NBA players with at least 100 field goal attempts this season, Smart ranks 338th in field goal percentage. Despite occasional hot streaks, Smart is shooting just 28.5 percent beyond the 3-point arc.

The key for Smart might simply be better recognition of where his best shots come from. The Celtics love using his size and toughness to take advantage of opposing guards in the post. Smart ranks in the 82nd percentile among all league players while averaging 1.024 points per play in post-up situations, according to Synergy Sports data. Only Al Horford has more post-up plays finished than Smart among Celtics players this season.

Smart is also shooting 43.3 percent (26 of 60) on corner 3-pointers this year, and his overall 3-point percentage is dragged down by his penchant for above-the-break looks (51 of 202, 25.2 percent) -- and, of course, his love of end-of-the-quarter heaves (eight of which have come from the backcourt and plenty more from maybe a step or two inside the center stripe).

As a primary ball handler with the second unit -- and the first-unit point guard this weekend with Thomas out with a knee bruise -- it's harder to sneak Smart into those post and corner sweet spots. Smart was 3-of-14 shooting in Friday's win. Two of his makes came in the paint while the other was a corner 3-pointer. Smart made all five of his free throw attempts in the game.

The Celtics, as a team, are currently on pace to produce one of the most efficient free throw shooting seasons in team history. Boston is shooting 81.2 percent at the line this season, which would rank third in team history behind only the 1989-90 (83.2) and 1990-91 (82.4) Celtics teams that had Larry Bird mingling near or above 90 percent at the charity stripe.

Boston ranks second in the NBA this season behind only the Charlotte Hornets (81.5 percent) in free throw percentage. Thomas ranks third in the NBA in free throw percentage at 91.1 percent, trailing only Paul George (92.4) and Steph Curry (91.6). Jae Crowder and Al Horford join Smart in shooting higher than 80 percent at the line this season.

Boston's opponents have shot just 76 percent at the free throw line this year, tied for the fifth worst mark in the league and leading to plenty of jokes about Boston's stellar "free throw line defense."