News of David Lee joining the Spurs came as a surprise. Since Lee was benched before the 2014-2015 season in Golden State in favor of Draymond Green, his reputation soured significantly. And the perception of his game continued downhill following a limited role in Boston to start the 2015-2016 season. Last February, Lee received a buyout from Boston, and joined Dallas for the cap-room exception.
But with the Mavericks, Lee performed well. He posted career-bests in player efficiency rating (24.0) and win shares per 48 minutes (.237). He was an effective small ball center with 8.5 points and 7.0 rebounds in just 17.3 minutes per game. A 25 game sample size --with injuries that kept him out of most of the first-round playoff series-- makes his productive stint with the Mavericks something less than a ringing endorsement. Skepticism aside, Lee proved he can still provide a scoring and rebounding punch in a limited role.
The concern with Lee has always been defense. Using the eye-test, Lee is constantly out of position, late to help, or beat off the dribble--a general negative on that end. His defensive ratings have been above 100 for his career (the lower the better), and his more passable defensive numbers result from playing alongside great defensive teammates. One clip is enough to get a sense of what he brings on that end:
The word porous comes to mind. At age 33, Lee's defense is unlikely to improve. However, he did start in 2013-2014 on a top 5 defensive team. Sandwiched between an elite defensive wing in Andre Iguodala and rim protector in Andrew Bogut, David Lee's individual letdowns did not significantly impact the team defense. His responsibilities were limited: the few that were able to penetrate the Warriors' defense successfully still had to face help, even behind Lee.
That was him playing the four. In a second unit for San Antonio, a plausible comparison to Iggy and Bogut would be a lineup of Patty Mills, Manu Ginobili, Kawhi Leonard, David Lee, and DeWayne Dedmon. Lee would be saved by the best defensive player in the league and an unproven yet emerging rim protector in Dedmon. That lineup would have four scoring options, and allow Lee to survive on the defensive end. Offensively, a Dedmon/Lee pairing is problematic because neither shoot the ball from long-range. Two lane-cloggers would hurt Ginobili and Leonard's ability to drive, allowing defenders to stay at home on Mills. Teams would be able to snuff out a Ginobili/Lee pick and roll with Dedmon's defender as extra help.
This means Davis Bertans is not getting minutes at the three or four--the Spurs are not going small with Kawhi at power forward. Maximizing Lee defensively is not favorable to the Spurs offensively.
Lee's best minutes in Dallas were as a small ball five. Dallas was able to space the floor and use Lee as a roller, diver, and dump-off option in the short corners. He was able to command the entire paint as a mobile scorer with Dirk as the stretch four. Lee is a good enough isolation player to draw occasional double teams, or make defenses pay for playing him one on one. Here's some footage against the Cavaliers last season that features all of the above:
Notice in each of these clips that the paint is left open for Lee to operate with or without the ball. Dirk is the only other big on the floor (in some of the clips), and his ability to shoot the three makes this work.
The equivalent is a lineup of Mills, Ginobili, Leonard, Bertans, and Lee (this would provide shooting on the perimeter). You can imagine a Ginobili/Lee pick and roll with Mills, Leonard, Bertans, or even Anderson and Simmons ready to shoot or attack--effective against second units. The Spurs would be able to run their 4 out 1 in motion offense and their weave and dribble hand-off sets with Lee as the sole interior player. Lee shot 50 percent in Dallas on two pointers 16 feet and out, making him credible on the pick and pop as well as the pick and roll.
Lee's defense as the center on second units around the rim is concerning, but how many teams have second unit centers that consistently beat you? Al Jefferson comes to mind, but the Spurs would counter with Dedmon. The Spurs also have the luxury of using Kawhi Leonard or Danny Green with their second units. Lee can be surrounded by players who prevent drives to the lane.
Overall, David Lee was signed as insurance. He can be a small ball five, play the four in the second unit, and also be used as a spot starter for Pau Gasol. Given Popovich's tendency to rest starters, Lee can better emulate Gasol in the high-low game with Aldridge than Dedmon. If Aldridge can extend his range to the three point line, Lee could play for stretches with the starters without compromising spacing.
At just $3.2 million for two years, the Spurs can only benefit from adding Lee. In an offseason that saw Tim Duncan retire, Boris Diaw traded to sign Gasol, and David West bolt for a chance to chase a ring with the Warriors, the Spurs were desperate for front court help. While the additions of Gasol, Dedmon, and Lee are imperfect, by committee they possess the versatility to play several styles. David Lee may not play a huge role, but he's an important part of the new-look big man rotation.