The dominant basketball story in Washington the past several years has been the ascendancy of Gilbert Arenas.  His legend should be familiar by now.  Underestimated and undervalued throughout his career, Arenas blossomed with the Wizards into a bona fide All-Star and one of the game?s most lethal offensive players.

The Wizards were dreck before Arenas arrived via free agency, but have gone to the playoffs each of the past three years.  And there?s no question that Arenas was the alpha player on each of those teams.

This season, Arenas played decently on a creaky knee still not recovered from surgery, then he re-injured the knee and has been forced to sit.  The Wizards lost their first five games, won three in a row with Arenas in the lineup, and went 17-12 without Arenas.

And so begins the murmuring ? The Wizards are better without Arenas.  They share the ball more.  They take better shots.  Arenas was a ball hog.  They play more of a team game.  Caron Butler was sublimating his game ? now that Arenas is out, we see what Butler can really do.

Each of these sounds logical and plausible.  But none of them address the real reasons why the Wizards have survived the loss of Arenas.

Last season, the Wizards finished with the league?s third most efficient offense and the 28th ranked defense.  They shot the ball a little worse than the league average but made up for it with solid offensive rebounding, not committing turnovers, and by getting to the free throw line.  On the defensive end, they were bad at everything except forcing turnovers.

This season, the Wizards are indeed a bit better than they were last year ? overall.  The improvement is not in any of the commonly cited reasons (improved ball movement, better shot selection, more ?sharing? of the ball), however.

Has the team?s shot selection changed significantly?  According to 82games.com, this season, 68% of the team?s field goal attempts have been jumpers, 26% have been ?close?, 4% dunks, and 1% tips.  The numbers for last season are identical.  In broad terms, the team is getting the same kinds of shots they?ve always gotten.

Is the team?s shot selection ?better??  This is tougher to quantify because ?better? can be subjective.  One of the best ways is to look at results.  And here again, the numbers don?t support the notion of better.  Last season, the Wizards had an effective field goal percentage (which accounts for the effect of the three-point shot) of 49.2%.  This season ? it?s 48.7%.

Shooting percentages on dunks and tips are basically unchanged.  This season, the Wizards are shooting worse on jumpers (.407 to .424) but a bit better on close shots (.605 to .586).  This change is almost certainly related to Arenas being out.  Wizards jump shots are now being taken by less proficient shooters while a greater proportion of the inside shots are being taken by higher percentage guys such as Brendan Haywood.

Are the Wizards ?sharing the ball? more this season?  Again, the numbers say no.  Last year, 54% of the team?s field goals were assisted; this season, it?s 53%.  In addition, the Wizards are turning the ball over more frequently without Arenas.  In 06-07, they were second best at protecting the ball; this season they?ve dropped to eighth.

One strength of the Wizards' offense in recent years has been getting to the free throw line.  This has been largely attributable to Arenas drawing fouls.  Last season they were sixth best at getting to the FT line; this season they?re 11th.

Overall, the Wizards' offense is less efficient than it was with Arenas.  Despite an improved Butler, a rock solid Antawn Jamison, and the reputed spread-the-wealth offense, the Wizards currently sport the league?s 13th ranked offense.  A year ago, with Arenas in the lineup, they were one of the best offensive teams in the NBA.

So, without Arenas on the offensive end the Wizards are shooting worse, committing more turnovers, and getting to the free throw line less frequently.  They?ve dropped from a top three offense a season ago to a little better than average this year.  And this against what?s been the league?s sixth weakest schedule to date.  This is ?better??

If the Wizards are demonstrably worse on the offensive end, how are they 17-12 without Arenas?  How are they still going to make the playoffs?  How did they beat the mighty Boston Celtics two in a row, including a gritty come from behind win in Boston?

The answer is simple ? improved defense.  This season, the Wizards have crept from the league?s defensive outhouse to about average.  They?re doing a better job of making opponents miss; they?re not worrying as much about forcing turnovers; and their emphasis on proper positioning has led to improved defensive rebounding.  The scheme installed by new Defensive Assistant Randy Ayers calls for consistent force rules to handle dribble penetration which makes life easier for rotating big men.  In previous seasons, the Wizards ran an array of defensive sets under the theory that multiple defensive looks could confuse opponents.  The simplified and more solid defensive scheme has made a big difference.

Note ? the Wizards' improved defense is NOT a result of Arenas being out of the lineup.  Tracking of individual defense through the early part of the season showed that Arenas was a much improved defender.  He did a better job of controlling penetration, contesting shots, and not getting out of position gambling for steals.

But what about Butler?  Surely Butler?s better play this season is attributable to Arenas being out.  Finally, Tuff Juice doesn?t have to sublimate his game, and we can all now witness the fullness of his talents.  Right?

Well, wrong.

What we know is that Arenas is out of the lineup and that Butler is playing the best basketball of his life.  One is not necessarily causing the other, however.

Consider ? this is Butler?s seventh season in the NBA.  He?s played for five different coaches (Pat Riley, Stan Van Gundy, Rudy Tomjanovich, Frank Hamblen, and Eddie Jordan).  To think that Butler is suddenly playing at a level that he could have played at all along if he?d only been given a chance is to also think that each of these coaches (and the front office executives who built the teams Butler has played for) fundamentally misjudged Butler?s abilities.  That includes Eddie Jordan, who under this theory apparently hindered Butler the past two seasons.

In his first two seasons in Washington, Butler used 23.2% and 23.1% of the Wizards? offensive possessions.  He was about average in terms of efficiency, producing 107 and 108 points per 100 possessions.  This season, Butler?s possession usage has edged up to 24.4% (a small increase), but his offensive efficiency has leapt to 115 points produced per 100 possessions.

In other words, Butler?s share of the Wizards? offense changed little with Arenas out of the lineup.  What has changed is his efficiency, and that?s tied primarily to improved shooting from the floor, from the free throw line, and from the 3-point line.  Butler is also handling the ball better ? a few more assists and a small reduction in turnovers.

Although basketball analysts typically love the most simplistic answer possible ? e.g. Arenas is out + Butler is better = Butler is better because Arenas is out ? the real answer is a bit more complex.  There?s nothing in Butler?s performance ? even when he was the leading player in Los Angeles when Kobe was injured ? to suggest he could be this efficient on the offensive end if only he?d been given a bigger offensive role.  This suggests that the improvement in Butler?s game is attributable to other factors, especially Butler?s work ethic.

This offseason, Butler worked extensively to improve his conditioning and diet, and he arrived at training camp lighter, stronger, and with greater stamina.  In training camp he talked of being in the best shape of his life.  This season, he fixed his diet, including cutting out high fructose corn syrup (in the past, Butler drank a two liter Mountain Dew during every game ? half before the game, half at halftime).  That?s helped him maintain his energy level throughout the full game.

Butler also spent hours this offseason working on his shot with the team?s new assistant coach and shooting instructor Dave Hopla.  In other words, better play from Butler is a combination of better conditioning, better skills, and an athlete entering his prime (historically, most NBA players are at their best from ages 27 to 32 ? Butler turned 27 last March).

Are the Wizards better without Arenas?  Well, the offense is demonstrably worse without him.  The defense is better because of an improved scheme implemented by a new assistant coach.  And Butler?s improvement is independent of Arenas? absence.

As a Wizards? executive told me, ?It?s absurd to think this team doesn?t miss Gil!?

Adding an Arenas playing at the level he did last season to this year?s squad would make for a formidable team that could do considerable damage in the playoffs.  Without him, the Wizards will hover around .500, and their season will be over by early May.

Kevin is a senior writer at RealGM.  He can be reached at kevinjbroom@gmail.com.