How does Antawn Jamison help the Washington Wizards? Some stats to consider

With Antawn Jamison set to make his season debut against Cleveland tomorrow, I thought I'd scan the archives on 82games.com and look at the type of difference Jamison's presence on the floor makes for the Wizards and for guys like Gilbert Arenas and Caron Butler.  These aren't meant to be conclusions, since the team dynamic now is far different than it was in, say, 2007, but they do provide some interesting food for thought.

Without further ado:

(And in case your wondering, bwoodsxyz will be back eventually, but has a personal matter he's been tending to these past couple weeks.  Nothing to worry about (it's actually a very good thing), just something that requires his attention).

One of the biggest talking points with Jamison is that his ability to spread the floor and score in so many different areas helped the rest of the team's shooting percentages.  The record shows that this point is unmistakably true.

Here is a list of the Wizards' effective field goal percentages since 2004/05 when Jamison has been on the court, compared to when he hasn't.

Interestingly enough, Jamison's effect was much more pronounced in the years Gilbert Arenas did play than in the ones he didn't.  Part of that may be due to the way Jamison and Arenas compliment each other on the court.  The shooting percentages of the Arenas/Jamison player pairing back this up, even though it took some time to get those up.

Jamison missed time in both 2004/05 and 2006/07.  In 2006/07, the Wizards leaned heavier on their Big 3 than ever before, so it shouldn't be a surprise that Arenas benefited from Jamison's presence, at least from the shooting department.

What about Caron Butler, you ask?  That's a bit more of a mixed bag.

I guess you could throw out 2008/09, but it's a bit troubling to me that Jamison historically hasn't had much of an effect statistically on Butler's shooting.  Butler's shooting has been simply dreadful this season, and if past history is any indication, it might take more than just having Jamison back to fix it. 

Nearly every Wizards player shoots above their season average playing in tandem with Jamison than playing without him

Overall,, Jamison tends to have an across-the-board effect in improving individual players' FG% from their normal season average. 

• In 2004/05, Jamison's presence resulted in a bump in FG% for every key rotation player except Arenas (barely), Kwame Brown, Etan Thomas and Michael Ruffin. 
  
• In 2005/06, only Butler (barely) and Ruffin shot worse among rotation players. 
  
• In 2006/07, only DeShawn Stevenson, Darius Songaila (in less than half the year) and Ruffin (in limited minutes) didn't see a FG% bump with Jamison in the lineup
• Jamison didn't have nearly as dramatic an effect in 2007/08: Only Songaila saw a major bump in FG% due to Jamison's presence.  Most players were pretty much at the same level with or without Jamison on the court.
• In 2008/09, Jamison's presence gave a significant bump to the following players' FG%: JaVale McGee (+2.5%), Etan Thomas (+2.5%), Andray Blatche (+1.6%), Dominic McGuire (+3.4%) and Javaris Crittenton (+1.8%).  He had basically no effect on Mike James and DeShawn Stevenson.  Only Butler, Nick Young and Juan Dixon saw their FG% drop with Jamison out there with him.
  

Obviously, that's not perfect, but for the most part, Jamison helps create better shooting percentages for the Wizards.

Jamison helps Arenas get more assists, but not Butler

Logically, it would seem Jamison helps get Arenas and Butler more assists because of his ability to finish quickly without necessarily creating his own shot off the dribble.  The stats back this up in Arenas' case, but interestingly enough, not in Butler's.

In Arenas' three healthy years, he has always dished out dimes at a higher rate with Jamison on the floor than his season average. 

That may not seem like much, but consider that Jamison and Arenas nearly always shared the court, due to both playing a ton of minutes for Eddie Jordan.  It's incredible that Jamison makes even that much difference in Arenas' assist rates considering how rarely the two played without each other.

That same logic holds for Caron Butler, yet we don't see the assist bump that you see with Arenas.

Once again, this provides evidence that it'll take more than Jamison's return to fix Butler's woes.

Jamison and rebounding

Jamison's ability to improve the team's total offensive and defensive rebound percentage when he's on the floor compared to where he isn't is a bit more of a mixed bag than I expected.  Consider:

• There are two years (2005/06 and 2007/08) where Jamison had a tremendous positive impact on both the teams' offensive and defensive rebounding.
• There is one year where he made a tremendous impact on the offensive glass, but not so much on the defensive glass (2004/05)
• There is one year where he had a tremendous impact on the defensive glass (crazy, even) and had a pretty significant negative differential on offensive rebounding (2008/09)
• There is one year (2006/07) where he didn't have much of an effect on either the offensive or defensive boards.

There are several reasons for this odd trend.  The Wizards were fifth in the league in offensive rebounding in 2004/05 but just 25th in defensive rebounding, so Jamison probably caught that bug.  2005/06 was when Etan Thomas missed a lot of time and Michael Ruffin caught the suckitude bug. 2006/07 was when Jamison was asked to leak out onto the break more often than he was asked to rebound.  2007/08 was when Jamison himself had the best rebounding season of his career.  2008/09 was, well, 2008/09.

Anyway, these stats are just meant as food for thought.  Use them as you all may.