Rookieball: A losing proposition

LeBron James and the Cleveland Cavaliers want to win now. To speed up the process, the Cavs are poised to part with No. 1 overall pick Andrew Wiggins (and 2013 No. 1 overall pick Anthony Bennett) as part of a blockbuster trade for Kevin Love.

Many league execs reportedly consider the Cavs' move unwise; dealing away potential stars on cheap rookie contracts is the GM equivalent of fingernails down a chalkboard. But there's a point in Cleveland's favor that's simply not up for debate.

Rookies rarely, if ever, help their teams win.

Gauging rookie impact

Last season, we introduced a metric, real plus-minus, designed to gauge the impact of each player on his team's net efficiency -- points scored minus points allowed (per 100 possessions) -- while mathematically adjusting for the effects of all on-court teammates and opponents.

Not surprisingly, LeBron's lofty plus-9.08 RPM rating led the league by a comfortable margin. But Love's RPM of plus-5.06 was also impressive and strong enough to place him among the top 10 NBA starters. It suggests he added about 5 more points per game to his team's scoring margin than the league average player.

Now let's look at the average first- and second-year RPM ratings of every player selected in the lottery since 2001. (That's as far back as our RPM data set extends.)

As shown, NBA rookies -- even high lottery picks -- usually post starkly negative RPM values. In other words, they are hurting their respective teams more than they are helping. Even among players drafted No. 1 overall, including luminaries such as James, Dwight Howard, Yao Ming, Derrick Rose and Blake Griffin, the average first-year RPM has been an uninspiring minus-1.0. That's the same as the per-possession impact of a mediocre bench player.

According to RPM, no rookie this millennium -- not even LeBron -- has had a major positive impact on his team.

The further we descend down the draft order, the lower the rookie RPM ratings fall. In fact, once we drop below the ninth spot in the draft, we find rookies contributing at about replacement level -- on par with D-League call-ups or guys signed off the waiver list.

Play tends to improve during the sophomore campaign, but the only draftees with a positive average RPM in Year 2 were those selected No. 1 overall. Among that elite group, only LeBron (plus-4.4) and Dwight Howard (plus-4.5) achieved truly elite RPM ratings by their second year in the league.

Win now?

While RPM measures player impact on a per-possession basis, a related metric -- wins above replacement -- factors in playing time to derive the total number of wins each player helps generate for his team.

As shown, high lottery picks -- even No. 1 picks -- just don't move the needle much their first season. The average top pick has yielded only two more wins than a minimum-contract replacement player.

The single most impactful rookie, Yao Ming, delivered only an extra 5.4 wins -- hardly enough to turn a lottery team into an instant contender.

A no-brainer

The bottom line: Drafting to "win now" is a fool's errand. Even future All-Stars usually require at least three or four years before they begin to play at a transcendent level.

Consider reigning MVP Kevin Durant. His first-year RPM was a horrid minus-3.2. His second year? A tepid minus-1.5. But in his third year it all came together, and he posted an elite RPM of plus-6.2.

Andrew Wiggins is no Kevin Durant. Even in a best-case scenario, he simply can't be expected to help his team win this season. And probably not the season after that either.

So if the Cavaliers want to maximize their odds of returning to the Finals while they have LeBron James under contract -- that is, in the next two seasons -- swapping Wiggins for Love is not only a defensible move -- it's a complete no-brainer.

According to the RPM numbers, the trade should be worth an extra 10 or more wins for Cleveland next season. That's enough of a boost to make the Cavs a legitimate title contender again.

RPM stats are provided by Jeremias Engelmann in consultation with Steve Ilardi. RPM is based on Engelmann's regularized adjusted plus-minus. Play-by-play data provided by Basketball-Reference.com.