There are really only 3 legitimate candidates for the title of best off-guard in the world. Kobe Bryant, James Harden, and Dwyane Wade. These 3 are clearly fan favorites, and are also roughly top 5 at their position, as far as advanced stats are concerned. Their will be two categories used to rank these 3 players. An objective approach (Stats) and a Subjective approach (the other stuff).
To determine which Shooting Guard is statistically the best, required a variation of the Win Score formula (Wages of Wins), and an added defensive component. This defensive component includes Defensive Rating and Synergy numbers. Since defense is such a gray area in the NBA, I made sure this defensive adjustment wouldn't overtly sway the results of the initial "Win Score" calculation.
"Win Score"=[Points + Offensive Rebounds + Defensive Rebounds *.5 + Steals + Blocks*.5 + Assists*.5 - Field Goal Attempts - Turnovers - Fouls*.5 - Free Throw Attempts *.44]
Remember, this is a simplified version of Dave Berri's "Wins Produced", a possession based player evaluating metric that can explain roughly 98% of all wins.
The numbers used for each players stats were Per 100 possessions, which were slightly different (and better) then their Per 48 minutes stats. The number below is the "Win Score" WITH the Defensive Adjustment.
Player Score
Dwyane Wade = 12.8
James Harden = 9.63
Kobe Bryant = 7.39
Prior to the defensive adjustment, Wade and Harden were very close. However, while James Harden got only a slight boost from his defensive acumen, Wade got a fairly large one. Kobe Bryant wasn't too far off in the beginning, but he registered a negative Defensive Adjustment, which created considerable separation.
Now for the Subjective stuff. While Dwyane Wade did indeed score the highest, he's also played the least amount of games and minutes. On the flip side, he's clearly missed a few games he didn't have to for, "rest and recovery" prior to the Playoffs. Both Kobe and Harden have played high minutes, but there really isn't enough separation from Wade to give them a significant edge.
There's also the LeBron James factor. Wade happens to play with the best player in the world, and while I haven't finished my analysis for the Heat yet, its clear Wade benefits from LeBron's presence. As illustrated by an earlier article I wrote however, its clear Kobe Bryant has benefited more from Dwight Howard's presence, then Wade has from Lebrons'. Harden is pretty much alone as far as super-star teammates are concerned.
The last topic discussed is "teammate-ness". Harden is pretty neutral on this front, as nothing really good or bad has come out about his persona. Kobe on the other hand, fails. Even Bryant himself acknowledges he can be a tough teammate to play with, and not ceding the team to Dwight is one of the reasons the Lakers are in dire straights. Wade on the other hand, has a solid advantage here. Putting team success ahead of personal glory makes Dwyane a teammate anyone would want to play with.
This leaves Harden as the winner of the "subjective" group. He's the only player of the 3 to consistently be the number one option or his team, and "carry" them to victory. While his Rockets clearly have some talent, Harden has gone above and beyond expectations by carrying them to a 6-seed in the West, and has a real possibility of leading an upset against a higher seeded favorite. He's played a lot of minutes, and seems like a good teammate.
In conclusion, this is still pretty hard. Dwyane Wade and James Harden are clearly the two best Shooting Guards in the world. Pound for pound, possession for possession, Wade is more effective. He's dynamic on both sides of the court, and a great teammate who puts the team above his own personal success. Harden on the other hand, means much more to his team then Wade, and has single-handedly (kind-of) carried them into the Playoffs. In my opinion, this is a toss-up. You can't go wrong with either guy, and your decision will likely come down to who you like more, then who the better player is.