Al Horford Is Just What the Celtics Need

After failing to land a star in a draft-day deal, Boston got a difference maker, signing Al Horford to a 4-year, $113 million deal. What kind of impact will he have on the up-and-coming Celtics?

Boston has spent the past few seasons stockpiling assets -- namely draft picks and cap space -- in the hope of landing a star player.

They did just that on Saturday, signing Al Horford to a mega-deal.

On it's face, this has a chance to be an excellent deal for both sides as Horford gives Boston an offensively diverse big man and some rim protection, two things the Celtics sorely lacked.

The price doesn't hamstring Boston, either. The contract constitutes 28% of Boston's salary cap in the first year of the pact, a number that will significantly diminish along the course of the deal as the salary cap continues to rise.

A jack-of-all-trades weapon and skilled two-way player, Horford was 20th in the league in offensive rating (scoring 114 points per 100 possessions) and 22nd in defensive rating (allowing 102 points per 100 possessions). His addition should help a 48-win Boston team continue its rise in the Eastern Conference.

Horford should also help the Celtics -- along with their treasure trove of future draft picks and oodles of cap space -- in their quest to nab another star, whether that's swinging a blockbuster trade or persuading Kevin Durant in free agency .

Adding a Diverse Offensive Weapon

Boston had three players finish with over 200 attempts from the paint last season: Jared Sullinger (49.6% field goal percentage), Amir Johnson (64.1% field goal percentage) and Kelly Olynyk (56.3 field goal percentage). Sullinger, currently a restricted free agent, attempted the most shots in the paint (296) while playing out of position as a center. Horford represents a huge upgrade as he converted his 317 paint attempts at a 70% clip.

Where Horford really excels is in the pick and roll, the staple of today's NBA.

In 2015-'16, Horford was involved in 301 possessions where he was the screener, more than double the amount of any Celtics player besides Sullinger (who had 165). Horford scored 340 points from this type of play and converted his shots at a 54.2% clip (57.1% effective field goal percentage). Sullinger netted 144 points on a 43% field goal percentage (45.7% effective field goal percentage).

Boston's most efficient roller was Johnson, who achieved 1.12 points per possession on a 60.3% field goal percentage (62.3% effective field goal percentage), which is similar to Horford's points-per-possession clip of 1.13. Johnson did it on 211 less pick-and-roll possessions -- making it easier to maintain a high efficiency rate -- and he recorded a turnover rate in pick and rolls (11.4%) that almost tripled Horford's (4%).

Horford expanded his game beyond the 3-point line last year, becoming lethal in pick-and-pop situations. After knocking down just 21 treys in his first eight seasons, Horford nailed 88 3-pointers at a respectable 34% clip a year ago.

Horford's all-around offensive skills, particularly in the pick and roll, will allow Boston coach Brad Stevens to get even more creative with his offensive sets.

Outside of the pick and roll, Horford also represents an upgrade in ball control, movement and transition. He has continually improved his turnover percentage over his career, achieving a career low 8.8% turnover rate last season, which would have ranked the second on the Celtics for players who have played over 1,000 minutes.

Even more impressive, while his turnovers have gone down, Horford's assist rate has kept improving, reaching 16.7% last season after he posted a career-high 18.6% assist rate in 2014-'15. Boston's best passing big man, by the numbers, was Sullinger, who registered a 15.5% assist rate last year. If Sullinger returns, he could pair with Horford to create one of the best passing frontcourts in the league.

Horford's transition game fits well with Boston's style, too. The Celtics played in transition on 16.3% of their possessions last year, the fifth most in the league, and Horford should help them become more efficient.

Despite the frequency of Boston getting into transition, the Celtics were extremely inefficient playing quicker.

Boston had a field goal percentage of 52.9% on transition plays (23rd in the league), an effective field goal percentage of 58.3% (24th) and accrued 1.10 points per transition possession (17th).

Horford should boost those numbers right away. In transition, Horford put up a 61.9% field goal percentage, 67.6% effective field goal percentage and scored 1.25 points per transition possession. His ability to create his own transition opportunities should be a boon for the Celtics, as well.

Finally, Horford also represents a massive upgrade for Boston's frontcourt at the free throw line.

While he gets to the charity stripe around the same amount as Boston's bigs did a year ago, Horford hit 79.8% of his free throws in 2015-'16, which represents a drastic improvement over Sullinger's (64%) and Johnson's (57%) free throw percentages.

Making a Great Defense Better

Boston was a very good defensive team last year, posting a defensive rating of 104.1 points per 100 possessions (4th in the NBA), causing opponents to turn over the ball 16.2 times per 100 possessions (3rd) and limiting opponents to a 48.7% effective field goal percentage (9th).

Horford is only going to help, and he will be an instant upgrade as a rim protector, which is the one glaring weakness in the Celtics' defense.

Boston gave up a defensive field goal percentage of 60.4% on shots from within 6 feet of the basket. Sullinger, who had the highest amount of attempts against him on the Celtics from that distance (4.1 shots per game), allowed 60.5% of those shots to fall. Horford allowed only a 55.6% field goal percentage while defending 6 of those shots per game.

As ESPN noted Boston's centers averaged just 0.6 blocks per game last season while Horford swatted away 1.5 shots per game. He should supplement their already elite perimeter defense, which allowed a 30.4% defensive field goal percentage on 3-point attempts (3rd in the NBA).


Horford's signing represents a huge upgrade in Boston's frontcourt from a statistical standpoint, but he also represents as a watershed moment for the Celtics by being one of the first big-name free agents to sign with the team. His commitment to Boston signifies they are capable of taking the next step and could influence others big-name stars -- a la Durant -- to give them a serious look.

A veteran with playoff chops, Horford is a difference maker on both sides of the ball and should help boost what is a promising young team led by a star-in-the-making coach. While Celtics fans were upset with general manager Danny Ainge for not making a big move during the draft with all of the assets at his disposal, this signing should erase some of those concerns.

Without a true star in a star-driven league, Boston ended last season ranked ninth in our power rankings. Adding Horford alone is unlikely to completely bridge the gap between the Celtics and Cleveland in the East, but he puts the franchise in position to continue its upward trend.