With several names in the running to be the top overall pick in the 2015 NBA Draft, the Sixers will have to weigh the idea of taking the best player available versus the best fit. In all likelihood they will end up choosing the former concept as opposed to the latter, just as they did last year. However, the two different ideas are probably more intertwined than people think.

It's no secret that Philadelphia is trying to build a defensive powerhouse, seeking out players with wingspan and athleticism to insert into their young core. With Nerlens Noel, Jerami Grant and K.J. McDaniels now in the mix, the team has really taken some leaps and bounds on the defensive end. The Sixers are first in the league in opponent turnovers, fourth in blocks per game, and have a defensive efficiency rating better than 60 percent of the league. That ain't shabby for a 12 win team.

In June's draft, General Manager Sam Hinkie is going to need to seek not only the best player available, but the one that best fits their system: a defensive force who can play multiple positions, as well as space the floor offensively. Kentucky's Karl-Anthony Towns would certainly fit that bill much better than Duke's Jahlil Okafor, the primary reason why I would draft Towns first overall.

There is no doubt Okafor is every bit a talented player people say he is. He is an incredibly gifted post player with an NBA-ready body, and good passing skills to boot. But where his game has the biggest holes is on the defensive end, and it's enough to justify the Sixers not selecting him first overall, if given the opportunity.

Despite an absurd logjam in the front court at Kentucky that has taken some of the playing time he deserves, Towns averages more rebounds and blocks per 40 minutes than Okafor does. For whatever reason, the strength and physicality Okafor shows on the offensive end does does not translate to the other side of the ball.

The 6' 11", 270 lbs. Chicago native hasn't shown much of an affinity for rebounding, and he's certainly not at a size disadvantage. His inability to box out correctly hurts his ability to create good positioning, which allows him be out jumped by other forwards. Here, Okafor lets Louisville's Montrezl Harrell linger around the paint instead of backing him out, and in turn Harrell is able to reach over him for the ball.

There are other times where Okafor simply makes little effort at all. In this case he actually locates where Mangok Mathiang is, but Okafor doesn't put his body on him. Mathiang slips by and pulls down the rebound, giving Louisville a second opportunity to score.

Unless uncontested or the ball falls into his lap, Okafor's inability to box out and position himself really limits his effectiveness defensively. Towns, on the other hand, is much more adept. He locates opponents well, creates leverage, and thus gives him the space to pull down boards.

While Okafor should -- keyword being should -- one day be able to fix this problem, what will really hurt him at the next level will be managing the pick and roll.

Although Duke plays almost exclusively in man defense, it's a rare occasion when he needs to leave the paint to defend. But in the NBA he'll need to come out to the perimeter to stop the pick and roll, and his footwork coupled with his poor defensive instincts will have teams picking on him. When trying to stop the pick and roll, one of the most important thing the help defender can do is read how is teammate reacts to the pick. If he gets through the pick, you fall back on your original assignment. If he doesn't, then you switch. Okafor does not read, he just reacts, and typically he pays the price.

In Miami's win over Duke, the Hurricanes were smart enough to pull Okafor out of the paint and make him defend the pick and roll. Here, Okafor not only commits the entirely wrong way, but he's too slow to even get back. It's an easy flush at the rim for the Canes guard.

Later in the game, Okafor actually keeps the ball handler in front of him, but his lateral footwork is so bad that Miami point guard Angel Rodriguez is able to blow past him. Okafor is forced to foul, and Rodriguez made both at the line.

Towns possesses the smarts to operate through the pick and roll, and is excellent at keeping quicker guards at bay. Watch him frustrate Florida Gators guard Kasey Hill on a switch.

That possession ended in a block for the New Jersey native.

Florida once again tried to use the pick and roll to target Kentucky's bigs, and Towns continued to shut down the Gators' guards. Despite taking a bad step left, Towns is able to use his quickness to re-adjust to cut off Hill, then blocks his attempted jumper.

With the prominence of the pick and roll in the NBA, and the Sixers lack of point guards who can defend it correctly, Towns is exactly what the Sixers need. Even offensively, Towns might make more sense for Philadelphia.

In general, Towns averages .995 points per possession, according to Synergy Sports. His touches offensively have been limited, especially in comparison to Okafor, but he has the skill set to become a good shooter. He's shooting 43% from mid-range (according to ShotAnalytics.com), and his nearly 78% shooting from the free throw line shows his shooting touch may be sustainable at the next level. Towns also averages .857 points per possession on catch and shoot situations, which is deemed average by Synergy, but it's hard not to see him being able to be able to knock down these shots regularly.

Because of Nerlens Noel's limited skill set outside the paint, and Joel Embiid's low post prowess, Philadelphia will need a big man who can space the floor. Towns is much more likely to be that guy than Okafor.

Come June, if Philadelphia gets the chance to select between Okafor and Towns, then they will have to figure out who will be the best player for their system. If the front office feels they can correct Okafor's holes on defense and limited shooting abilities, then the Duke standout will likely be their selection.

But right now, Karl-Anthony Towns looks like the best player available to excel in Philadelphia's system.