Al Horford’s defensive renaissance

The Boston Celtics asked a lot of Al Horford on the defensive end of the court last year. He was simultaneously the team’s most switchable big man, presumed rim protector, and overall organizing force.

He didn’t always have to wear all of those hats at once. If Horford was paired with Amir Johnson, he was free to chase around smaller perimeter-oriented opponents. When he played alongside Jae Crowder, he could focus more on rim-protection. Kelly Olynyk and Tyler Zeller forced him to walk a tightrope between both, and at times the pressure of switching roles was too much.

Take a look at how he gets caught in between responsibilities against the Cavaliers.

This isn’t an entirely fair example. Cleveland forces opponents into difficult decisions constantly, but they weren’t the only team that made life difficult for Horford. The Celtics defended at only a mediocre rate when he was on the court, the first time a team with Horford on the roster performed at a level anything less than elite in years.

Some of that can be attributed to playing in an entirely new context. The Hawks teams that Horford left behind had several very good defensive players and a razor sharp coaching staff.

The same was most assuredly true in Boston last year though, and yet Horford never found a real rhythm with his new squad. That’s changed to start this season. The Celtics are currently ranked first in defensive efficiency, and have allowed just 96.5 points per 100 possessions with Horford on the floor.

The question thus becomes, what’s changed? The simple answer is nearly everything. The Celtics only returned four players from last year’s team. To compare their season to date with the previous year’s campaign isn’t exactly apples to apples.

The nature of the inquiry limits us as well. Quality defense is contingent upon keeping things from happening, which makes it difficult to fully understand, and even more challenging to quantify.

Not to mention the fact that we should certainly be skeptical of whether or not anything has really changed just yet. It’s possible that this is all a result of small sample size. The defense looks stingier, stouter, and more aggressive this year though, and the fun crushing realities of statistics shouldn’t keep us from searching for emerging trends.

So let’s put forth a hypothesis. Not a declarative statement, or an assumed truth, but simply a premise to test out across the course of the year. Here it is:

In 2016-17, the Celtics simply did not have the right personnel to leverage what it is that makes Horford a special defender- switching, helping, and organizing the troops to defend the pick and roll. Boston overburdened him with duties, and attempted to construct a system that leveraged the strengths of its tenacious on-ball defenders.

Now, in 2017-18, that system has been rebuilt around collective length, allowing for more switching, increasing the value of a rangy, versatile big like Horford, and decreasing the number of split second decisions he’s forced into making. The result has been, and will continue to be, a more cohesive and effective defensive unit.

To put it more simply, the new roster suits Horford nicely. He’s playing better because of it, and the Celtics are benefiting dearly. There’s enough smoke here for this observer to be intrigued. Feel free to share your thoughts on the matter.