Behind the Numbers: The Unimportance of Assists?

Posted by KCarpenter on January 19th, 2011

Pittsburgh, as Syracuse most recently learned, is a contender to win the national championship because they do one thing incredibly well and a lot of other things at a pretty high level. The one excellent thing they do is crash the offensive boards. They lead the nation in offensive rebounding rate, which is the driving force behind their current position as the most efficient offense in the country.  The Panthers do a lot of other things well– shooting, defensive rebounding, controlling turnovers– but nothing they do, in terms of advanced stats, really jumped out at me until I noticed that they are second in the nation in assists to field goals made. 69.8% of Pittsburgh’s field goals are assisted. This is interesting and pretty cool, but I began to wonder if it even mattered.

Assists are really weird, because in a way that’s not true of any other individual stat, they don’t really measure individual performance at all. To get a credited assist, the passer’s teammate has to knock down shots. Surround a healthy Kyrie Irving with four clones of someone who shoots as well as I do, and as crisp, creative, and well-timed as his passes are, he is not going to get too many assists, solely because, well, I am a terrible shooter.The box score for this game will show he got no assists. Did Kyrie have a bad game? Were his passes worse than usual?

Jamie Dixon's Team Moves the Ball Well

No, probably not, and that’s a tricky question. From close to the beginning of basketball box scores, assists have been tracked. In fact, in the early days of individual statistics, assists were really about the only thing tracked besides points and rebounds. Why do we even track assists? Maybe just because we always have. On some level, it’s easy to see what assists are supposed to do: assists are supposed to be a measure of play-making through passing. But as I mentioned, assists really aren’t all that great at measuring true ball movement because the statistic is hopelessly tangled up with field goal percentage. A team that makes more shots should generally have more assists. We don’t keep track of who made a great pass that led to a missed shot, and that really throws off our view of skilled passing and playmaking, which, after all, assists are supposed to measure.

There are more problems than that. We largely assume that assists are almost always positive. Passing is good. The problem is that sometimes it isn’t. Let’s suppose that we are on the fast-break, and I have the ball and my man beat. It would be easy for me to hit an uncontested layup. Instead, I drop the ball back to you, and you hit a slightly more difficult uncontested mid-range shot. I decreased the chance of us scoring with that pass, but got credited with the assist. That was a bad assist and these happen all the time. If you don’t believe me, watch Rajon Rondo “gun” for assists the next time you watch the Boston Celtics play.

Read the rest of this entry »

Share this story

Behind the Numbers: On the Issue of Home Cooking…

Posted by KCarpenter on January 12th, 2011

Conference play has started and it is a glorious thing. While non-conference play has its charms (who doesn’t love to see heavyweights go at it?), conference play has a special allure. Games are exciting when there is history, and that’s what conferences offer: a history of rivalries and past meetings that add a little bit of spice to each new meeting. And while old wounds may ache, it’s the new ones that sting: The best part of conference play is the home-and-away series; to better understand  the meaning of Duke and Ohio State’s close scrapes this past week, we need to understand home cooking.

Home Cooking, the Way Mom Used To Do...

“Home cooking.” When we talk basketball, we understand that this phrase is a euphemism for home-court advantage, a catch-all for the widely-discussed yet still mysterious phenomenon. Teams win more when they play on their home court. This is a fact. It’s the “why” that’s much more complicated, and there are many explanations. The “home cooking” euphemism itself is a partial explanation, metonymy for all the comforts of home: sleeping better in your own bed, being able to stick to your own routine, and, of course, literally getting to eat a home-cooked meal. Taken altogether, the psychological benefits of these things (coupled with the converse disadvantage of opponents lacking these things) is supposed to account for the edge that comes with playing at home. Of course, savvier or maybe just more cynical people hear “home cooking” and their minds turn to matters more sinister than mom’s meatloaf. “Home cooking” to these folks means referee bias in favor of the home team. The innocent and idealistic amongst us shudder at the thought, but the harsh reality is that referee bias is real.

Kyle Anderson and David Pierce in a 2009 article published in The Journal of Sports Sciences outline a series of systematic referee biases in men’s college basketball. In addition to being more likely to call fouls on the team with the lead and on the team with the fewest fouls, referees really do call more fouls on the visiting team. Also, oddly enough, these effects are more pronounced when the game is on national television. But, of course, home court advantage is bigger than just getting a few fouls going in favor of the home team, isn’t it?

Read the rest of this entry »

Share this story

Behind the Numbers: The Buckeyes Are Ready

Posted by KCarpenter on January 5th, 2011

Kellen Carpenter is an RTC contributor. 

(ed. note: this article was prepared and written prior to Ohio State’s Tuesday night win over Iowa)

When is the appropriate time to start talking seriously about which team is going to win it all? I know that everyone wants to hear predictions before a single game is played and that can be a fun exercise, but how often does it yield any actual insight? Pre-season polls have their place and wiser minds than mine find at least one pre-season poll very useful and interesting. That said, polls and summer hype can lead to some pretty silly results, as pre-season First Team All-American Harrison Barnes is happy to remind you.  So when do we know that a team is win-it-all-good? After they blow out a bunch of cupcakes? After a strong showing in a pre-conference tournament? Do they need to have beaten at least one tough, quality opponent? Do we need to wait for conference play to start? For it to be halfway through? To end? Should we even bother making predictions at all?  Of course,we should: predictions are fun and if we make them too early, who cares? If predictions were always right they wouldn’t be fun. So, in that spirit, it’s time that we start talking about how good Ohio State is.

Winning is Fun, and OSU is Doing a Lot of It

But, wait: wasn’t everybody already talking about how good Ohio State is? Well, yeah. Rush the Court, the AP, and ESPN/USA all think that Ohio State is the second best team in the country behind also-undefeated and still-rolling Duke. That said, they may be better. The electronic seers that Ken Pomeroy has captured and employed now seem to think that Ohio State is the best team in the country, and looking at some of the numbers, I can’t help but nod my head and praise the wisdom of our future robot overlords.

Ohio State has the third most efficient offense in the country and easily the most efficient defense. How good is the defense? The current mark is better than any team, ever, since Mr. Pomeroy started crunching adjusted defensive efficiencies in 2003. They have been, so far, amazing on that end. Thad Matta’s team seemingly never fouls and barely ever sends their opponent to the line, actually leading the sport of college basketball in this category. They force turnovers at a hellacious rate (27.4%, 3rd in the country) and that same gritty defense has held their opponents to 45.3% effective field goal shooting. They are among the best in the country at securing defensive rebounds, thereby limiting opponents’ second-chance opportunities. This is not a forgiving defense.

On offense, the Buckeyes are devastating as well. Looking to keep the national player of the year crown in Ohio, Jared Sullinger has been a force of nature. He shoots the ball at a very efficient clip, he rebounds effectively on both ends, gets to the foul line and rarely turns the ball ever. The ridiculous numbers he’s been putting up aren’t a function of him taking a ton of shots or the team playing at a fast pace (Ohio State, unsurprisingly for a team in the Big Ten, plays at a pretty pokey speed). The ridiculous numbers Sullinger has been putting up are mostly a function of Sullinger actually being ridiculous. He’s not alone either.  Jon Diebler is having the most efficient season of anyone in college basketball on the offensive end. He isn’t shooting a lot, but when he shoots, the ball goes through the hoop. Right now, Diebler is maintaining an other-worldly 74.6% true shooting mark, largely driven by his 51.2% three-point shooting. This isn’t a small sample size fluke either: Diebler has already taken 86 threes this season.  Outside of Sullinger and Diebler, the Buckeyes have plenty of quality offensive options. William Buford, Aaron Craft and David Lighty are all strong playmakers and skilled shooters making the entirety of the starting lineup potentially dangerous.  Freshman Deshaun Thomas has been a pleasant surprise, providing outstanding offensive rebounding from the bench. When a team can surround the likely national player of the year with such an effective arsenal of weapons, what else can be done?

Read the rest of this entry »

Share this story

Behind the Numbers: Rebound, Rebound, Rebound

Posted by KCarpenter on December 29th, 2010

Kellen Carpenter is an RTC contributor.

One of my favorite features about watching basketball on television is when the cameras try to take you inside the locker room at halftime or inside the huddle during timeouts. This inside peek theoretically should be endlessly fascinating and unceasingly cool. I initially hoped to watch the coach draw up the next play, talk about strategic weaknesses he’d noticed, and generally be smart and insightful about the game. Of course, anyone who has ever seen a single one of these “inside peeks” knows that my hopes are routinely dashed. Inevitably, because the networks won’t actually broadcast any of the juicy strategic content of the huddles or halftime speeches, we instead get clip after clip of hoarse coaches exhorting their players to rebound, rebound, rebound, while the players gulp down water and nod with intense understanding. This is, of course, hilarious. Certainly the coach doesn’t think, “My players don’t know they are supposed to rebound,” while the players think “Rebounding! Of course! I was just going to stand around and ignore the ball, but your way is so much better!” It’s just an absurd little bit of theater since everyone knows how important rebounding is. Of course the players are trying to get the rebounds. Why wouldn’t they?

DeJuan Blair Was a Rebounding Machine at Pitt

Rebounding has a cost. We tend to think of rebounding in terms of what it can grant a team: on the offensive end, a rebound offers another chance to score while it deprives the opponent of the same chance on the defensive end. Rebounding isn’t free, however. When a team attempts to rebound the ball, there is a trade-off. Every player who goes for an offensive rebound isn’t getting back on defense as quickly as he can, potentially giving up fast break points to the opposing team. Conversely, every player who attempts to get a defensive rebound isn’t leaking out, trying to get those high-percentage fast-break points. The potential cost of rebounding is forsaking fast-break points for your own team while giving up those same points to your opponent.

But does that matter? Offensive rebounding is important. When the shots aren’t falling and your opponents’ shots are, getting extra possessions is how you win games, and coming up with offensive rebounds is easier than getting steals or forcing other turnovers. In college basketball, the teams that win the championship are almost universally excellent at offensive rebounding. Does it have to be that way?

Not necessarily. In the NBA, the San Antonio Spurs dominated the early part of the last decade, winning four championships between 1999-2007,  even while largely forsaking offensive rebounds. Gregg Popovich made the unusual though clever decision to avoid crashing the offensive boards and instead emphasized getting back on defense, preventing the opponent from scoring any fast break points. While San Antonio often trailed the league in offensive rebounds, in those years the average field goal percentage of Spur opponents sunk to ridiculous lows. Likewise, until fairly recently, San Antonio didn’t emphasize fast breaking, choosing instead to focus on securing the defensive rebound and limiting their opponents’ second chance opportunities. Instead of emphasizing their own offensive efficiency, the Spurs chose to gleefully flummox their opponents’ offensive plans. Those four NBA championships speak to the strategy’s success.

Read the rest of this entry »

Share this story

Behind the Numbers: Who Needs to Shoot More Threes?

Posted by KCarpenter on December 22nd, 2010

Kellen Carpenter is an RTC contributor.

A wise man was once asked why he shot so many threes. The sage stroked his chin and replied simply, “Because there are no fours.” Truly this is the wisdom of the ages. While there are some amongst us who dispute the wisdom-dispensing qualifications of former Kentucky Wildcat/Boston Celtic/Miami Heat Antoine Walker, there is at least a hint of a whiff of a smidgen of truth to his sentiment. The three is a powerful and deadly offensive weapon and the proper deployment of judicious three-point shooting can transform a tough team into a deadly team.  This isn’t a secret. Lots of teams know this. How many March upsets follow the familiar script of an overmatched, smaller team launching a barrage of threes in a bid to upset its major-conference opponent? Most of them. But it’s not just underdogs that utilize the three, it’s the top dogs too: Duke’s tremendous early season success is due in no small part to shooting a blistering 43.6% from beyond the arc so far this season. The three is potent, indeed.

Employee #8 Never Hesitated on a Trey Attempt

Yet, for some reason, many teams shy away from the three. Why? The three is mighty, and sometimes a player or a whole team can become drunk on its power, letting loose a barrage of deep shots only to have the shots not fall. The barrage of bricks, airballs, and just plain ugly shots can grind an offense to a halt. Fairly or not, some coaches disparage the three and discourage their players from taking what they see as a relatively low-percentage shot. In their eyes, the three is imprudent and hasty, the product of players not having the discipline to work the ball around the defense, to set up a shot closer to the rim for a “high-percentage shot.” It’s hard to fault coaches for wanting their teams to take the best shots they can get, but sometimes, in trying to avoid the risk of the three-point shot, coaches are actually turning down the real “high-percentage shot.”

Three-point shots, as you may have noticed, are worth one point more than a regular field goal, and because of this mathematical fact, hitting two out of five three-pointers or hitting three out of five standard field goals nets you the same result: six points on five shots taken. Dazzling arithmetic, I know, but I just want to be crystal clear on this so I can make the point that it’s easy to compare the relative efficacy of shooting twos versus shooting threes by simply taking the three-point shooting percentage of a given player or team and multiplying it by 1.5. This is the essential wizardry behind the concept of effective field goal percentage (eFG%) and the trick we are going to use to figure out which teams would be better off shooting more often from behind the arc.

If a team’s actual two-point field goal percentage is lower than the three-point field goal percentage multiplied by 1.5, it suggests that the team’s better offensive option is shooting the three. If you were to run this basic check on all 345 teams that Mr. Ken Pomeroy quantifies, you’d see that a whopping 246 teams get more offensive bang for their buck from shooting threes. Now, this is a really crude calculation with an even cruder suggestion: if you are effectively better at shooting threes than shooting twos (which most of you are) you should take more threes. This advice ignores a lot of variables like which shots are open, who is open to take those shots, and the difficult-to-measure value of a balanced offense. In many cases, coaches realize how valuable the three-point shot is and are taking those shots at a rate that they feel is most effective for their offense. In these cases, it’s not inherently interesting that the effective three-point percentage happens to be a little higher than two-point percentage; it’s simply a matter of chance with a fairly ambiguous interpretation. What’s much more interesting is to take a look at teams where the numbers are less ambiguous: teams that are much better, relatively speaking, at taking threes than twos, yet insist on ignoring that evidence anyway.  (see table below)

Read the rest of this entry »

Share this story

Behind the Numbers: The Coming Decline

Posted by KCarpenter on December 15th, 2010

So, let’s play a game. I tell you that I’m going to flip a coin (let’s say a 2009 U.S. quarter) exactly thirty times. Your job is to guess how many times that the coin is going to come up “heads.” Very cleverly, you notice that that typically a coin comes up heads about 50% of the time, so you should guess that, in this game, you will get heads about fifteen times. Okay, so I flip the coin the first five times and, surprise of surprises, I end up getting heads four out of five times. Does this mean you were wrong? Does this mean that the coin will continue to turn up heads at a 80% clip? Of course not. It’s just that variance is “magnified“ in small sample sizes. If we flip the coin the full thirty times, it’s almost certainly going to turn up heads less than 80% of the time.

Obviously, we are here not here to talk about flipping coins, but rather college basketball. So, what’s the relevance? The relevance is that right now, we are about a third of the way through the college basketball season and people are pointing to extraordinary statistics and acting as if they are going to hold up through March and April. The coin won’t turn up heads 80% over a big enough sample size, and Pittsburgh won’t continue to grab 47.9% of offensive rebounds against its opponents. Some of the extraordinary stats in college basketball are simply due to small sample size. Some teams tasting truly rarefied air in December are destined to fall back to Earth come March. Who’s due for a decline?

Glad you asked. What I’ve done is checked up on who was the leader on the offensive and defensive ends of the court in regards to each of Dean Oliver’s Four Factors at the end of the 2009-10 season. Then, I checked Ken Pomeroy’s rankings to see which teams were currently performing better than the very best team from last year. The logic is simple (and admittedly a little simplistic): It’s unlikely that many teams this season are going to perform too much better than what the best team in a given category did the year before. Unsurprisingly, at this point early in the season, there are quite a few teams performing better than any team performed last year. Let’s break it down category by category and figure out which teams are cruising for a bruising. Or a decline in efficiency. One or the other.

Effective Field Goal Percentage

None of these teams are shooting that much better than 2009-10 Denver (57.9%), but still, betting on Kansas or Georgetown’s shooting to cool off isn’t a bad bet. It’s a little early to predict Duke’s shooting to decline, but if Kyrie Irving’s absence isn’t explanatory enough for you, here’s another reason.

Read the rest of this entry »

Share this story

Behind the Numbers: The Counterintuitive Result of the Syracuse Zone

Posted by KCarpenter on December 8th, 2010

Kellen Carpenter is an RTC contributor.

While theoretically, the intricacies of basketball should provide for a near-infinite array of offensive and defensive strategies, we instead see a surprisingly few varieties of essential approaches. On the defensive end, simple man-to-man defense is the primary defense of the vast majority of college basketball teams. Other types of defense are less common, but the clear runner-up in terms of defensive schemes is 2-3 zone defense, which is usually what TV and radio people mean when they say “zone defense.” More specifically, when radio and television people refer to “the zone” they probably mean the version of it that is run by Jim Boeheim in Syracuse, and with good reason.

Hands Up in the Syracuse Zone (P-S/D. Nett)

It takes only the mildest interest in college basketball to know that Syracuse under Jim Boeheim has been a perennial contender for the national championship. Year in and year out, the young men in orange appear ready to take all comers each and every March. And aside from the constants of Boeheim himself and a steady flow of NBA-caliber talent, the other constant is the zone. Boehim isn’t just an accomplished practitioner of the zone, but a certified guru. His mastery of this defensive system and ability to impart that system to others has made him a coach in demand. When Mike Kryzewski needed a coach to teach the US Olympic team about the zone, Boeheim was the natural choice. The curmudgeonly coach, Syracuse, and the zone have merged into a monolithic juggernaut that seem destined to befuddle under-prepared offenses come tournament time. As such, the question of how to execute zone defense effectively isn’t as interesting to most teams as how to overcome it.

Now, on the topic of attacking a zone, I don’t have the benefit of the advice of smart scouts, assistant coaches, and the strategic gurus who are working hard to win their respective teams’ games. Instead, I get the second-hand advice of guys who are on television and radio, ex-coaches and ex-players, and the most pernicious and dangerous of strategic advisers, basketball writers. These folks tend to repeat, in unison, some familiar refrains. It’s almost inevitable that when I hear or read someone talk about the zone, they mention the same weaknesses: vulnerabilities to perimeter scoring and offenses that run through the high post. It’s what they seem to say almost every single time, and that’s fine. These approaches make sense when you watch the ball move against the zone: the ball is passed into a player at the high post, sucking in defenders from the perimeter or near the goal, and opening up either a three-pointer from the corner or a quick pass to a baseline-cutter making a move to the basket. So, a solid piece of conventional wisdom, right?

Well, maybe not. The mind is a funny thing, prone to remember triumphs more clearly than failures and generally to overestimate probabilities and degrees of success. Fortunately, even if our subjective memory and evaluation of past events isn’t reliable, we always have the box scores to turn to, and to those we shall turn. If the advice of the pundits and analysts is accurate, teams that run the zone defense should expect to have their opponents make three-point shots against them at a pretty good clip.

Read the rest of this entry »

Share this story

Behind the Numbers: The Thin White Line and Foul Theory

Posted by KCarpenter on December 1st, 2010

Kellen Carpenter is an RTC contributor.

Moneyball isn’t the founding document of sabermetrics; that honor probably belongs to Bill James’ Baseball Abstract. That said, the reason that most baseball fans know about the advanced, modern approach to baseball statistics is because of Michael Lewis’s nearly 300-page story about the Oakland A’s. Well, they know either because of the the book itself or the uproar and debate around it. In any case, Moneyball was and remains a cultural phenomenon, a true breakthrough into the mainstream. Because of Moneyball, baseball and the dialogue around baseball has gotten smarter.

Battier Represents an Efficient Player Without Huge Stats

Basketball hasn’t had a single watershed moment like Moneyball. Progress in the advanced stats movement has come in fits and starts. Unsurprisingly, the closest thing to a mainstream breakthrough for advanced statistics in basketball came from Michael Lewis. “The No-Stats All-Star” was published February 13, 2009 in the New York Times, and focused on the world of advanced stats in basketball through the microcosm of the Houston Rockets player Shane Battier and his general manager, Darryl Morey. The article introduced the larger world to lots of fun ideas like offensive and defensive efficiency and adjusted plus/minus. It had a few interesting smaller nuggets too, and today we’ll be taking a look at one of those.

According to Morey (and the research), the worst possible outcome of a defensive play is to foul. In fact, Morey mentions that they identify other teams in the NBA that make use of the modern numbers-based thinking by looking to see which teams make a consistent and radical effort to avoid fouling. It’s a simple check, but one that makes sense: of the Four Factors that contribute to defensive efficiency, opponent’s free throw rate is the easiest to control. Telling a team to not foul is an easier instruction than “rebound better!” or “reduce your opponent’s effective field goal percentage!”

In any case, Morey’s observation made me curious as to which teams in college basketball make use of that mantra and consistently avoid fouling. To make sure that I didn’t wrongly consider a fluke year, I looked at the average team opponent free throw rate from 2006-10. For those keeping score at home, free throw rate is calculated by dividing attempted free throws by attempted field goals (and multiplied by 100 to get a slightly friendlier percentage). The average free throw rate for Divison I schools over the past five years comes in at 37.1%, while the fouling-est team registered a 54.3% and the best, least-fouling-est team managed a mere 23.3%.  [the complete and fully sortable list is located here as a Google Doc] Now, to name names: The top four teams who foul the least in order: Ohio State, Siena, Connecticut, and North Carolina. Three of these teams are perennial championship contenders and Siena is one of the most successful mid-majors of the past few years. The rest of the teams near the top of the list are a little more scattered. The top thirty teams on the list are an odd admixture of regular contenders (Syracuse, Florida, Arizona), mid-major spoilers (College of Charleston, George Mason), and middling teams of all sizes (Central Connecticut, Samford, Notre Dame, Boston College). So that’s interesting, but inconclusive.

But, what about the bottom of the list? Is there any discernible trend amongst the teams that foul the most? Well, here, the picture is clearer. The bottom seventy-five or so teams are almost exclusively small conference schools that have had middling success at best, though the true booby prize goes to Central Michigan, who, from 2006-10 averaged an opponent free throw rate at an astonishing 54.3%. So while it’s unclear that rarely fouling is the true mark of a great team in college basketball (though it does appear to have helped some very good teams), fouling a lot seems to be the mark of pretty bad to thoroughly mediocre teams.

Read the rest of this entry »

Share this story

Behind the Numbers: Do Blowouts Predict Champions?

Posted by KCarpenter on November 24th, 2010

Kellen Carpenter is an RTC contributor.

It’s been a hard-fought game. Every shot contested, players from both teams diving all over the court for loose balls, the crowd whipped into a frenzy. Bitter rivals, ranked teams, and it all comes down to one buzzer-beating shot. This is a good game. This is why we watch college basketball. Who wins? Who cares? Rhetorical questions can cut two ways, and this one is particularly vicious in matching it’s semantic zig with meaningless zag. On one hand, we gladly affirm the joy-of-the-game sentiment: Close games are their own reward, and if both teams played hard, we can walk away with a zen-like comfort at having seen a beautiful competitive spectacle. That said, there is a colder reading, one that isn’t as much fun, but may be just as important: Close games between evenly-matched teams don’t mean much of anything, it doesn’t tell us anything about how good either team is. No matter what is marked down under the team records, win or lose, the game is basically a tie.

Teams That Win Close Are Nice, But Teams that Dominate Are Better

Maybe you are preparing a protest: pulling out a tough win shows force of will, late-game execution, grit and guts. These are the best wins, you argue, because it shows you that the team knows how to win when it really matters. A team that can win when the going gets tough can win no matter the situation. Well, okay, hypothetical protester, time to drop the biggest open secret that everyone not on television knows: margin matters and, in terms of predicting future success, a win by one means about the same as a loss by one.

This makes sense with a little bit of thought. Basketball games are a long series of events each contingent on probability, and probability is a fickle mistress. Consider our hypothetical one-point game: In the second quarter, the power forward for one of the teams manages to take a barely-contested ten foot jumper and he has a 50% chance of making the shot. Half the time it goes in and half the time it doesn’t, the rest of the game unfolds in the same way and because of that one event, the team either loses or wins. In every other way, the team is just as good or just as bad as we always knew it was. One shot doesn’t actually change that. Did Butler lose the National Championship because they missed the final shot? Maybe, but they also missed eleven other three-pointers over the course of the game. Hitting any one of those would have won the game.

Is this an oversimplification? Yes, but it all speaks to a simple idea: That the difference between a one point win and a one point loss is really almost white noise. The idea isn’t just a philosophical buzz-kill, but rather a philosophical buzz-kill with implications: Winning by a little doesn’t mean much, but totally dismantling an opponent means a lot. If a team wins by twenty points, it means that they are very likely better than that opponent. Instead of just one lucky shot, they had ten lucky shots, and if you have that many lucky shots, then chances you aren’t so much lucky as good. There is meaning in blowouts. This is why just about every serious advanced-statistical ranking system takes into account margin of victory. That said, we don’t need to tear wide open Ken Pomeroy’s magical tempo-free machine to fully understand this principle, and instead, for an illustration we can turn to a different sort of numbers game.

Read the rest of this entry »

Share this story

Behind the Numbers: New Duke, Same As the Old Duke?

Posted by KCarpenter on November 17th, 2010


Kellen Carpenter is an RTC contributor.

Last year, as you are probably aware, Duke won it all. They enter this season as the easy top pick in all the national polls and the consensus favorite to cut down the nets in the early spring of 2011. With Kyle Singler and Nolan Smith sticking around for one last hurrah, a sensational recruiting class starring the incredibly skilled Kyrie Irving, and Coach K masterminding things as usual, picking Duke as the best team in the country is pretty easy. Duke is going to be very, very good this year. Here’s the real question, though: Will this year’s incarnation of the Blue Devils be as good as last year’s? The consensus seems to be yes, but there is reason to  lend an ear to dissenting voices crying out from the wilderness.

The reason has to do with offensive efficiency and may need a little explaining. Last year Duke was easily the most efficient team in the land on offense. They did this not by shooting the lights out (though they shot well), but by each player making sure they did other things to help their team on offense. Let me clarify: when I talk about “offensive efficiency,” I am talking very specifically about the Dean Oliver conception of it, which is a simple measure of how well a team scores per possession given a key Four Factors. The Factors are effective field goal percentage, turnovers per possession, offensive rebounding, and free throw rate. So while Duke was only moderately good at shooting the basketball last season (#92 in D-I), they made their opportunities count by rarely turning over the ball (#15 in D-I) and rebounding their misses at an astounding rate (40.3% of misses, good for #7 in D-I). The low turnovers and superb offensive rebounding are what made Duke’s offense so efficient and deadly, despite good-but-not-great shooting and a very average rate of getting to the free throw line (#158 in D-I for those who care).

Duke May Miss This Big Guy More Than Expected This Season

So, here is where we get to the trouble: Duke’s success at preventing turnovers and getting offensive rebounds, which strongly drove Duke’s overall success, depended largely on the efforts of two players. Those players, in case you can’t guess, are the departed Jon Scheyer and Brian Zoubek, to whom the Blue Devils are probably more indebted to than they realize.

Obviously, while Scheyer was the team’s leading scorer and his scoring contributions will be missed, his value to Duke went far beyond points. Scheyer was the team’s primary ball-handler and play-maker and did this ball-handling and play-making virtually mistake-free, which is astonishing. Despite having the most opportunities for a turnover, Scheyer coughed up the ball less than any other player on the team. Now while Nolan Smith and Kyle Singler should rightfully be credited for their skill at taking care of the ball, let’s be clear: Scheyer’s mistake-free play-making will be missed, and as good as Kyrie Irving is, it’s highly unlikely that a freshman point guard will be able to match Scheyer in this regard. It’s in fact very likely that the Blue Devils will turn the ball over a lot more than last season.

And if it’s very likely that turnovers will go up, it’s almost certain that offensive rebounds will go down. The incredible success of Duke at offensive rebounding is almost entirely owed to Zoubek, who not only led the ACC in having a name that sounds the most like a Pokemon but also was the best offensive rebounder in college basketball. By way of example: Duke had eleven offensive rebounds in the championship game against Butler, and Zoubek had six of those. This type of performance from the 7’1 big man was the norm. Now, Zoubek is gone, and his heirs in the frontcourt have yet to display anywhere near his level of skill at yanking down misses. While Zoubek grabbed 21.4% of the Blue Devils’ misses, the next best rebounder, Miles Plumlee, managed to grab only 11.1%. Mason Plumlee’s 9.1% and Ryan Kelly’s astonishingly poor 2.9% don’t offer much cause for hope either. These numbers considered, it seems very unlikely that Duke will be able to match last year’s incredible effort on the offensive boards.

Turnovers will probably increase and offensive rebounds will probably decrease, which means offensive efficiency is facing a drop, even if Duke somehow manages to keep up its world-class defense and replace all other lost offensive production. Now, am I saying Duke is going to be bad? No, I’m not. Duke will be very good, but unless a couple things happen, they won’t be in the same class as the national champion 2009-10 team. What we are probably looking at is something closer to  the 2007-08, or 2008-09 vintage Duke, which is good for about the same regular season record but with a few more particularly surprising losses and a much shorter postseason. That said, here are some other things that could happen: Duke’s shooting this year could be so good that drops in offensive rebounding and a rise in turnovers could be totally offset. Kyrie Irving and the other rookies could be even better than John Wall and the Kentucky freshmen were last year, making everyone forget  about Scheyer and Zoubek. Either of those things could happen. The conclusion is this, though — lots of things go right for Duke and I never count Coach K out, but the improbable is improbable, the unlikely remains unlikely, and “could” isn’t the same as “will.” That’s as true in Cameron Indoor as anywhere else in America, so let’s pack up our laurel wreaths and anointing oils until 2011.

Share this story