How the Spurs Will Beat the Warriors

Random statistic alert:

9 to1.

Before this year, that's how many times the Spurs had played the Lakers in the playoffs versus how many times they played the Warriors. During the Duncan era, the Spurs have played the Lakers six times, not including the first round this year. The last time San Antonio faced off against Golden State, it was 1991, and Duncan was 14. David Robinson was in his second season, the highest-paid player on the Spurs roster, raking in $2.27 million that year. Avery Johnson earned a whopping 50 grand. Check out Stampler's epic piece for a more in depth, humorous breakdown of that series. Needless to say, things have changed since then.

On Monday night at the AT&T Center in San Antonio, the Spurs will shift from a series against one of their most familiar postseason foes, to one of their most unfamiliar. Granted, this year's Lakers hardly resembled their championship teams from the last decade, especially without Kobe, though Jack Nicholson hasn't changed much. Nonetheless the Spurs are set to face the ambitious and rising Warriors, a team with four rookies and three sophomores and an average age of 25 years, 8 months, and 12 days. A third of the Warrior's roster hadn't been conceived, born, or potty-trained when these two teams last met in the playoffs. And how about this: The Warriors could sign Dr. J and still be younger than the Spurs, whose roster currently is about as youthful as it has ever been.

The point is that these Warriors are uncharted playoff territory, even for a veteran team like the Spurs. What's more, their style of play is rather unusual, spearheaded by the unconventional shooting/wizardry of Stephen Curry. His ability to nail the deep ball, assisted or unassisted, and make all manner of other difficult shots, places a heavy burden on the defense of Warrior's opponents. The Spurs will likely have to handle Curry by committee, as confirmed by Manu Ginobili via Dan McCarney of the San Antonio Express News:

Manu said basically everybody's going to get a shot at Curry at some point in the series.

— Dan McCarney (@danmccarneysaen) May 4, 2013

The good news? The Spurs own the Warriors. During the Duncan era, the Spurs are 46-9 against the Warriors, and have NEVER lost to them in San Antonio. They haven't accomplished this against any other team.

The bad news? The Warriors are rolling, surprising most NBA fans and experts by dismissing in 6 games the Denver Nuggets, heavily favored in part because of their league best 38-3 home record. What's more, Stephen Curry has responded very well to the intensity of his first playoff experience, shooting a higher field goal percentage and scoring more points in those six games than his season and career averages.

So the question burns: "How will the Spurs beat the Warriors?" Does that seem like a dumb question with an obvious answer? It might be, because even Jalen Rose knows that if Curry keeps playing this way, the Warriors are a tough out. But it might not be. Perhaps there are other things that keep the Warriors humming. David Lee, Andrew Bogut, Klay Thompson, and Jarrett Jack are NOT scrubs or even close. Surely they make a significant contribution to the success of the Warriors, right? I mean, obviously the Warriors' offense is Curry-centric, but the Spurs should also target and neutralize those additional devices which allowed Golden State to vault into the conference semis.

In my last piece, I explored the idea of correlation and significance in assessing which individual contributions are strongly associated with the Spurs' margin of victory. Some of the results were obvious, and others were not. I'd like to angle that analysis towards the Warriors. We know who drives the bus (hint: It's not Festus Ezeli), but we also want to examine which players make a significant contribution to the Warriors, and how. Stopping Curry will be the primary defensive focus, but it wouldn't be a bad idea to have a couple of back up plans in case he catches fire. For the analysis, I'll focus on the Warriors as a whole in addition to breaking down significant contributions from each player. For more reading on the series, read Mr. Gomez's thoughts on the matchup as well.

The Warriors live and die by the assisted triple

Stephen Curry can create his own shot, even from deep, but the Warriors are most successful when they are making threes and dishing assists. They shoot the highest three point percentage in the league at 39.9%, though they are somewhat middling in assists (59.4% assisted FGs, ranked 16^th). Ironically, the strength of their offense also happens to be the downfall of their defense. The Warriors are susceptible to allowing assisted shots and give up a high rate of three pointers. In fact, they are worst in the league at allowing triples; 27.6% of their opponents shots are threes. They are in the bottom quarter of the league in allowing assists; 21.5% of their opponents' possessions end in assisted buckets.

To help us better understand the "love-hate-triangle" the Warriors have with the triple and assist, let's bring in the concepts from my previous article. First, a quick refresher on the coefficient of correlation, R, and a measure of significance, p:

R, a value whose magnitude ranges from 0 to 1, measures the strength of association between two variables. A large, positive R indicates that two variables are directly proportionate. A good example of two variables with an R near +1 would be shoe size and height. A negative value of R indicates that the variables are inversely proportionate, that is, when one increases the other decreases. The closer R gets to -1, the more oppositely related the two variables are.

The value of p indicates the probability that the correlation defined by R occurs due to chance. As such, a lower p suggests that the correlation between two variables is not random. Generally, when p is less than 0.05, we say that the correlation between the two variables "significant." The lower p is, the more significant that relationship becomes.

With that in mind, let's examine those statistics which are significant to the Warriors margin of victory, both positively and negatively.

The three-pointer certainly is important to Golden State, but the assist even more so. Golden State is an elite three point shooting team, but remember that they are just average at generating assists. What these results suggest is that when the Warriors are able to climb into the elite strata of assists, they are highly competitive.

Conversely, a high number of opponent assists just kills them. A correlation of -0.64 indicates a very strong negative association between margin of victory and opponent assists. What's more, this is an extremely significant result. Teams that score a large portion of their buckets via assists, they are much more likely to beat the Warriors, who struggle to prevent assisted baskets.

This is great news for the best assisting team in the league. The Spurs average 25.1 assists per game, and 89% of their triples are assisted. The Warriors are 10-18 when they allow more than 25 assists. The Spurs also do a great job of limiting their opponents' assists, ranked 5^th in the league in opponent assist rate.

So, before we move on to the Warriors individual contributions, let's start with this: It's a pretty solid bet that the Warriors will beat you if you allow them to shoot uncontested threes. To beat the Warriors, the Spurs need to close out and force them off the line, while generating assisted buckets and a high rate of threes of their own. That's exactly what you want to hear as a Spurs fan, because that precisely describes the refrain of their offensive and defensive mantras.

Corralling individuals

So we know how the Spurs need to control the Warriors as a team, but what about the individual players? Let's apply the same investigation here, while changing a few things. Thanks to suggestions by some commenters on my previous post, I altered the analysis of individuals so that non-percentage statistics were normalized by minutes played. This reduces between-variables bias, since statistics like points and field goal attempts are highly correlated to minutes played.

It turns out that a wide variety of individual contributions are significant to the Warriors offensive success, and only one category (shooting) involves Stephen Curry.

These are interesting results. We can see that Stephen Curry's shooting is significantly correlated to success, but it's further down the list than I would have expected. At the very top is David Lee's assist rate. While Curry generates most of the assists for the Warriors, Lee is still one of the best passing bigs in the league. When he leaves the court, the Warriors assist percentage drops by more than 10%. Lee's assist rate is closely followed by Harrison Barnes' defensive and total rebounding. Barnes is an athletic player who gets the kind of rebounds where, if he didn't get them, the opponent would. Considering Lee's and Barnes' skill sets, I think Kawhi Leonard is going to be much more important in this series than against the Lakers. His ability to keep Barnes off of the glass and disrupt passing lanes from Lee and Curry will be tantamount to a solid defensive effort from the Spurs.

A word of caution about interpreting these results: Confounding variables nearly ALWAYS play a role in statistical analysis of sports. Beyond simple statistical measures, nearly every data breakdown of sports requires some stipulations. For instance, from the list above, Klay Thompson appears to be more significant as a shooter than Curry. But the caveat is that, without Curry's constant threat as a shooter, Thompson wouldn't get open looks. Because of the respect Stephen Curry demands on the perimeter, other Warriors shooters sometimes get loose. Thompson is sort of like the Danny Green of the Warriors, though with an admittedly higher ceiling, and he is one of the reasons the Warriors live and die by the assist. When Klay Thompson hits assisted triples, which are available because of Curry's presence on the court, the Warriors are one of the top 6 teams in the league.

The numbers confirm this. In wins this year, Thompson shot 45.4% overall and 45.0% from three. In losses, those numbers plummeted to 37.6% and 33.0%, respectively. Curry, on the other hand, saw less than a 3% dip in FG% in losses, and actually shot better from deep. The Warriors also get 4 fewer assists per game in losses. You can be sure that Thompson's misses are responsible for a good portion of that dropoff.

Danny Green will bear the substantial onus of forcing Thompson to pass or at least step off the three. If Thompson consistently gets open, assisted looks, the Spurs may be in trouble.

The Spurs are made for this

Some, including myself and Tom Haberstroh ($), postulate that the Knicks were built to beat the Heat. Not that they coincidentally have all the pieces to challenge them, but that the roster was intentionally constructed to match the vaunted Big Three from South Beach and their bevy of veteran shooters. Obviously the members of the Spurs weren't assembled to dominate the Warriors, but if you suddenly woke up from a 15 year coma and saw this matchup, you might believe it to be true. The Spurs have all the pieces to handle the Warriors offensive attack, and the exact offensive scheme which stresses the Warrior defense. Even Stephen Curry thinks so. Of all the matchups he has faced, Tony Parker is his least favorite. Danny Green and Kawhi Leonard are the prototypical defenders for Thompson and Barnes, and Tim Duncan should be able to abuse Bogut on the inside. If the Spurs win the assist battle every night, which I think they will, they shouldn't lose a game. That being said, Curry might have one of these nights, so I expect the Warriors to win one of their home games and probably keep the other close. It won't be a cakewalk like each of our last three -playoff-series-not-against-OKC, but if the Spurs stick to what they do well, they should be golden.