Sunday, November 15, 2009

Fantasy vs. Reality

Fantasy hoops are a big deal, as Yahoo and ESPN can attest. And with each season, the fantasy leaguers get increasingly numerous and serious. There is a growing intelligentsia of fantasy aficionados -- some of whom get their own shows on NBA TV -- and a number of professional fantasy-focused websites. (See [Full disclosure: HOSS's brother is a contributor to WinMyFantasyLeague.]

This writer is not immune to the fantasy hoops bug (although my team, Turkoglicious, has been an early season disappointment). But one thing that consistently irks me about fantasy hoops is how poorly fantasy stats translate to real life, and vice versa. Exhibit A: Troy Murphy is considered a fantasy stud. Yahoo Fantasy ranked him 35th overall in its pre-season rankings, one spot behind Carmelo Anthony, and ahead of Rashard Lewis (36th), LaMarcus Aldridge (40th) and Carlos Boozer (44th) . In real life, would anyone take Troy Murphy before those three players? On the flip side, there are guys like Shane Battier and Luis Scola, who are very good players and great at the so-called intangibles (ball-on-ball defense, help defense, diving for loose balls) for which there are no statistics. As a result, Shane Battier is ranked a distant 135th.

There seems to be a few reasons for the fantasy/reality divide. First, unlike baseball, which is really an individual sport masquerading as a team sport, basketball is a quintessentially team game. But there is no stat for "making your teammates better", or if there is one, it is imperfect. An assist means you made a pass that led a teammate to score. But there are plenty of ball hogs who have high assist numbers simply by virtue of having the ball in their hands so much (see, e.g., Allen Iverson.)

Turns out there is a whole range of basketball skills that aren't accounted for in any traditional statistics, while some traditional statistics are completely misleading. Although steals and blocks are "defensive" statistics, they do not measure the quality of a defender's ball-on-ball defense. Steals are especially misleading. Again, take Allen Iverson, who loafs all game on defense and then and gambles on steals a few times a game: his steals stats were high but his defense lackluster throughout his career. Similarly, rebounds can be highly misleading. Of course, team rebounding is immensely important, but any post player will have 6 rebounds a game simply by virtue of standing near the hoop, and rebounds off a missed free throw are one of the easiest stats to accumulate in pro sports. As long as fantasy GMs and real GMs focus on traditional stats, fantastic defenders like Shane Battier will always be undervalued. Traditional hoops statistics give you a myopic view of the player's skill or value to the team.

Efforts to expand basketball stats beyond the traditional have been choppy at best. The +/- stat, the holy grail for some hockey statisticians, turns out to be a highly dubious stat. How does Kevin Durant have one of the worst +/- stats in the league last year? Is he a detriment to his team or are his teammates so in awe of his ability that they just stand around doing nothing on offense? The likely answer is probably 'none of the above' -- but simply that +/- is not a useful stat for measuring NBA players' skill level or value to the team.

Some people have tried to devise new statistics that do a better job of capturing a player's value. ESPN analyst, John Hollinger, has devised a methodology for determining a player's actual value, called "Player Efficiency Rating" or "PER". The PER is built on traditional statistics, but adjusts for minutes played and for the team's pace of play. Although Hollinger stats are useful because they allow you to compare two players who average different amounts of minutes-per-game and play on teams with different styles, they still do not account for difficult-to-measure skills like ball-on-ball defense -- arguably one of the most important basketball skills.

There is a movement among some GMs to take basketball statistics to the next level. Some are lifting a page out of Billy Beane's playbook (of Money Ball fame) and attempting to do for basketball what a select group of young baseball GMs have done for baseball -- i.e., devise a modernized, analytical approach to determining a player's true value by using advanced statistical tools. Daryl Morey, GM of the Rockets, is an early adherent. Morey has not revealed his methodology, but if the success of the T-Mac-less-&-Yao-less Rockets is any indication, Morey is on to something.

This issue, however, remains an open debate. We, at JPO, would love to hear from our readers. What is the best way to measure a player's value to his team? Your answers can be general (e.g., Hollinger's PER) or position-specific (e.g., John Stockton once said that the way to measure a PG was to look at the FG% of his team). Post your responses in the "comments" section to this post.


Bhel Atlantic said...

Hollinger's PER is not much better than traditional stats, as it is basically a linear combination of various offensive statistics. It does little to account for defensive performance, other than rebounding.

I would think Adjusted Plus-Minus is the simplest way to judge a player's worth.

Perhaps one day fantasy leagues will include performance categories such as "Charges Taken" and "Drives Intimidated." Until then, the Murph man (and Andrea Bargnani) will get much love from me on my fantasy teams.

Justin said...

For perimeter players, I think you need to examine the offensive results of the opposing players. For example, an anti-fantasy player Thebo Sefolosha did an admirable job on Kobe at the end of the game back on November 3rd, by making him take bad shots and causing Kobe to turn the ball over. For big men, its tougher because a lot of their blocks and altered shots come on help defense. Perhaps, points in the paint of the opposing team could help evaluate a big man's defense.

Btw, I would love to see 'charges taken' as a fantasy stat.

H.O.S.S. said...

Thanks for your comments, Justin.

I think we have an emerging consensus that "charges taken" should be a fantasy stat.

Your point about Thebo on Kobe is equally prescient. Perhaps a defensive stat that considers how the perimeter player fared against the top 10 scoring players at his position? If you consistently hold Kobe, Lebron and D-Wade under 30, shouldn't that count for something in the boxscore?

Bhel Atlantic said...

In an article published today, Charley Rosen, my favorite curmudgeon, identifies several defensive tasks that go unquantified in traditional statland:

"Because there are no statistics that measure good defensive rotations, showing to positive effect on the weak-side of screen-and-rolls, helping on weak-side screens, getting back on defense, bad shots forced, shots intimidated, passes denied, boxing out, deflections in passing lanes and so on, truly effective defenders are largely ignored."