Locked in a Cell on an Island


Aapo Haapanen | flickr

I remember reading—this was a few years ago, before the teachings of the Sloan Conference had drifted to the West Coast and implanted themselves in this impressionable young mind—that Nnamdi Asomugha, then a cornerback for the Oakland Raiders, was the singular elite and dominating force at his position from 2008-2010. It seemed like an editor’s error: Asomugha had managed only two interceptions across those three long years.

But, as I’d learn: in order for a cornerback to get an interception, the quarterback’s pass must be thrown towards the wide receiver that the cornerback is covering. And if the quarterback is deciding to throw it towards a certain wide receiver, it means that, for at least a moment, the quarterback saw a promising opening between the cornerback and wide receiver.

So there are actually two ways that a cornerback can never catch interceptions while playing on every down: (1) Have wide receivers blaze right past you, catching balls and scoring touchdowns that you never had hopes of laying a finger on. Or (2) Cover the wide receiver so thoroughly and completely from the moment the ball is snapped so that the quarterback would never dare throw the football towards that wide receiver—perhaps even willingly chucking the ball out of bounds instead of testing fate.

Asomugha’s meager interception totals are due to factor (2).

From 2008-2010, Nnamdi played in 45 of his team’s 48 games, playing virtually every defensive down, and usually against the other team’s best wide receiver. Over those 45 games, Asomugha was in coverage during 1,266 pass plays from opposing offenses. Out of those 1,266 passing plays, quarterbacks only threw the ball in his direction a total of 87 times (about once per half). Of those 87 passes, wide receivers caught only 50 passes (about one per game), including just 1 touchdown. The greater his influence on a football game, the smaller his statistical footprint.

NFL teams had figured that the best way—or perhaps it’s just the least-worst way—to deal with Asomugha’s presence was to toss out gobs of the offensive playbook. To concede Asomugha’s slice of the field to Asomugha, to effectively sacrifice that wide receiver to Nnamdi’s smothering coverage and try to make something work with the shrunken field that remains. Bravado would only lead to inefficiency.

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One would think that NBA teams would operate with the same tactical philosophy when calling offensive plays in the low post. Much like the wide receiver-cornerback matchup, the post-up is a one-on-one matchup of strength, agility, and cunning technique—with size and length replacing football’s requirement for breakneck speed. Also like a quarterback throwing the ball to a certain wide receiver, the post-up is a matchup that is entirely initiated and instigated by the offense. It’s up to the offense and the offense alone to decide whether or not they will test that elite defender or, most wisely, when and how often they will test the weaker ones.

Here are the five best centers and power forwards so far in 2013-14 in terms of Points Per Possession allowed on plays where they’re defending in the post.* For reference, Josh Smith scores 0.69 points per possession in plays when he attempts a 3-pointer. These are the Nnamdi Asomugha’s of our basketball generation.

  • Brook Lopez – 0.32 ppp
  • Ronny Turiaf – 0.43
  • Kenyon Martin – 0.49
  • Omer Asik – 0.57
  • Bismack Biyombo – 0.59

And here are the centers and power forwards at the bottom of this year’s pile. For reference, LeBron James scores 1.34 points per possession in when he shoots in transition.

  • Joel Freeland – 1.22 ppp
  • Gorgui Dieng – 1.27
  • Jeff Adrien – 1.3**
  • Udonis Haslem – 1.36

*Amongst players must have defended at least 25 post plays. 

**This number only includes Adrien’s play in Milwaukee after his midseason trade from Charlotte. 

The gap in quality of defending is pretty enormous. To post up on any of the defenders in the first list is, in essence, to throw a possession away. Those defenders are not totally impenetrable fortresses, no. Somebody did manage a touchdown on Nnamdi, and these guys do allow baskets—from time to time. But these baskets only come on fortuitous bounces after three or four possessions of thonking one’s skull against a brick wall. One would think that NBA offenses would give them the Nnamdi treatment, would specifically avoid sending their big down low, to use their precious possessions towards more promising ends.

Kenyon Martin has been posted up every 15.4 minutes so far this season, while the other four elites (Lopez, Turiaf, Asik, Biyombo) have all been posted up somewhere between every 12.0 and 12.9 minutes of play. Meantime, here’s how often the slow-footed four—their weakness at defending the play by this point totally verifiable–have been posted up:

  • Joel Freeland – 15.3 minutes per post play
  • Gorgui Dieng – 9.6
  • Jeff Adrien – 9.4
  • Udonis Haslem – 16.2

All of my samples here—from the number of players examined to the number of post-ups each has defended—are, admittedly, quite small. But this is puzzling: why do NBA offenses post up Joel Freeland and Udonis Haslem less frequently than they do Ronny Turiaf and Omer Asik? It’s like throwing the ball into Nnamdi’s shadow-tight coverage and crossing your fingers in hopes for the best.

Because even in their own small samples, scant dozens of post-up plays on the season, the five bigs at the top of the PPP leaderboard have delivered an impressive string of disruptive highlights. When they get posted up they don’t cause missed shots as much as they cause turnovers, frustration, and pestilence. The offenses can keep testing their post defense in perpetuity. They’ll be waiting, down low, to feast:

Football statistics via National Football Post. Basketball statistics via Synergy Sports. 

Miles Wray