On the eve of his 21st season ending, Dirk
Nowitzki made it official that his impressive NBA career is finally over. In a year that
featured another legend, Dwyane Wade, embarking on a farewell tour of his own, the loss of
Nowitzki still looms large. While both are shoe-ins for the Hall of Fame, Nowitzki’s
annual dominance came in ways that quite literally changed the way NBA basketball is played. In some ways, Nowitzki was a one-man, evolutionary
force over his two decades in the league. Entering the NBA at just 20 years old in 1998,
Nowitzki was just a skinny teenager with a jumpshot. During those early years, NBA big
men were tasked with more laborious tasks — rebounding, blocking shots and both defending
and scoring on the block. In his rookie season, the only 14 players over 6’9” shot at
least 50 3-pointers. And most of them, at least in that stage of their career, were
fairly one-dimensional, long-range specialist like Clifford Robinson, Matt Bullard, Danny
Ferry and Donyell Marshall. By 2005, a year before his first Finals appearance,
Nowitzki had established himself as on the NBA’s preeminent stars and was earning annual
invites to the NBA All-Star game. Not coincidentally, Dallas had flipped from being one of the league’s
most pathetic franchises to a 50-win juggernaut. The league clearly noticed that skilled big
men like Nowitzki were quite helpful. That season, the number of players 6’9” or
taller shooting at least 50 3-pointers per season had nearly tripled from Nowitzki’s
first year — from 14 to 39. In part because of Nowitzki, the NBA entered
the era of the “stretch big.” During the mid 2000s to the middle of this current decade,
teams began phasing out unskilled big men for those who could spread the floor (diagram
1). While there were certainly other reasons for this shift, the fact that the Mavericks
were a fixture atop the Western Conference — including winning the title in 2011 — due
to the impact of Nowitzki was clearly not lost on the way NBA team’s shaped their
frontcourts. But while that impact was more broad, Nowitzki
also impacted the NBA in more acute, tactical ways that could be seen on a game-to-game
basis. Though Nowitzki will go down as one of the best shooting big men in the history
of the sport, to think of him as just a shooting specialist would be a mistake. Most “stretch
bigs” featured some type of Shakespearean fatal flaw. Players like Minnesota’s Anthony Tolliver
remained a specialist because he wasn’t a threat to post up. The Ryan Anderson’s
of the NBA never reached Nowitzki’s level because of their inability to get to good
shots when chased off the 3-point line. And the vast majority of stretch bigs simply could
never match Nowitzki’s level as a shooter. It’s mostly because of that last part that
Nowitzki created an entirely new tactic in the NBA — the nail iso (Diagram 2). When a shooter like Nowitzki comes to screen
for the ballhandler — known as a pick-and-pop — it typically creates a problem for opposing
defenses if they stick to a coverage that keeps both defenders guarding their own men.
But one coverage, “switching”, tends to be the most effectively nullifier of pick-and-pops
that NBA defenses turn to. By simply letting the smaller player switch onto the bigger
shooter and the bigger player swap onto the smaller ballhandler (Diagram 3), a defense
can avoid any tricky maneuvering and force the opposing offense to attack the switch
or run another action as the shot clock ticks down. Switches effectively shut down the ability
of player’s like Anderson and Tolliver to hurt a defense with their shooting. But part of Nowitzk’s greatness is that
he found a way to beat that too. Before Dirk, players posted switches in one of two areas:
on the block or slightly higher on the wing (diagram 4). Early in his career, Nowitzki
tried to beat switches in that same traditional way. The problem with attacking a switch that
way is the complications involved. If Nowitzki encounters a switch in a middle
pick-and-pop and tries to post up on the block, a lot can happen between the switch and the
Nowitzki getting the ball. Depending on alignments, defenses could “switch out”, swapping
defenders on Nowitzki yet again as he rolls his smaller defender toward the block (Diagram
5). They could also front and flood (diagram 6) or simply deny any reversal passes aimed
at creating a better angle to throw the ball to Nowitzki on the block (diagram 7). After a few seasons of this, Nowitzki’s
first head coach, Don Nelson, had an idea: instead of having Nowitzki try to post up
middle pick and pop switches on the block, he’d do it right at the nail — hoops lingo
for the middle of the free throw line (Diagram 8). That maneuver essentially eliminated all
the complications, allowing Nowitzki to walk his smaller defender down a few steps, get
a clean catch and go to work (Diagram 2). Before Nelson and Nowitzki joined forces to
do this, it hadn’t happened in the NBA. Nowitzki essentially created the nail iso.
Nowadays, seeing superstars post up at the nail is somewhat commonplace, especially when
it comes to switches in the middle of the floor. But without Nowitzki, we may have never
seen it. What’s even more incredible is that this
tactic also withstood the analytics revolution. Taking a shot around the nail falls into the
dreaded mid-range category — the area of the basketball court with the least efficient
return on shots (diagram 9). But Nowitzki has been so uncannily accurate from that distance
that he’s made those high-arcing jumpshots from around the nail and efficinent shot. Many Hall of Fame players like Nowitzki is
destined to be have used their signature style of play and impressive accomplishments to
leave their mark on the game. Nowitzki, however, has quite literally left his mark — all over
the whiteboards of NBA coaches for two decades.