Possession Margin: 2011 NCAA Lacrosse Tournament Quarterfinalists (Hempstead Region)

If you're reading up on this weekend's games, you're probably seeing dozens and dozens of words about face-offs and that they're going to be a huge key to every team's opportunity for success.

From 10,000 feet, that sentiment is correct: Capability at the dot provides a lot of advantages -- it allows teams to control momentum (getting on a run and stopping a run), it allows teams to immediately get the ball into their offense's hands, and it allows teams to establish the pace of play. 

In the end, what I think people are trying to get at when writing about face-offs as a key to success is that draws serve an important role in generating a high possession margin (i.e., having more offensive possessions in a game than defensive possessions).

I don't necessarily disagree with this position.  Face-offs are a huge key to establishing a high possession margin, and it's not outlandish to think that teams that have a high possession margin in a game are more likely to win.  It's an issue of opportunity: I would want my team to have more chances to score than my opponent.

Where I think the emphasis on face-offs gets constipated is when you look at possession margin at a more granular level.  There are, in fact, three ways to generate an offensive possession:

1. Win a face-off (duh);
2. Successfully clear the ball at the end of a defensive possession; and
3. Create a failed clear via the ride during an opponent's clearing attempt.

So, face-offs are part of the possession puzzle, but they're not the only puzzle piece.  Teams can generate possessions in all kinds of different ways, and the quarterfinalists in this year's NCAA Tournament really embody that.  Moreover, for some of the teams in this year's post-season, dominating the possession margin hasn't been a huge issue for them.  For those squads, their efficiency when a possession is actually occurring (rather than their play in actually generating the possession) has buoyed them to success.

Let's address the eight quarterfinalists and figure out: 1) How they're generating their possession margin; and 2) Whether their possession margin per game is significantly important to their success on the field.

JOHNS HOPKINS

Possession Margin Per Game: 6.3 (1)
Face-Off Percentage: 60.61% (3)
Clearing Percentage: 85.29% (19)
Riding Percentage: 81.66% (25)

How is Johns Hopkins Generating Possessions?

The Blue Jays' incredible possession margin rate is attributable to almost one guy: Matt Dolente.  Dolente has been absolutely dominating at the dot this season, holding a face-off percentage right around 67%.  Hopkins isn't doing an amazing job on either their clear or their ride; what is creating the giant gap between the offensive possessions they play per game and the defensive possessions they play per game is Dolente's incredible efforts on the draw.

How Important is Johns Hopkins' Possession Margin to Their Success?

Important, but only because it makes the Blue Jays really destructive.  Pietramala is rolling a really young defensive unit out onto the field every game, and while they've been very efficient this season -- the Blue Jays are fifth-nationally in adjusted defensive efficiency -- it's always a good thing to limit defensive exposure for a unit that is still establishing its maturity.  Johns Hopkins has done a great job of limiting such exposure this season as only four teams in the country play fewer defensive possessions per game than the Blue Jays. 

Where I think Hopkins' ability to control the possession margin is less important is that the Blue Jays have one hell of an efficient offense.  With guys like Kyle Wharton, Chris Boland, Zach Palmer, John Ranagan, and John Greeley, Johns Hopkins is rolling with the 10th-most efficient offense in the nation.  So, Johns Hopkins doesn't necessarily need lots of offensive possessions per game to score; they're coverting at a high rate when they actually have the bean.  What the possession margin does for this team is that it allows the offense to really put a lot of tallies on the board and run up the score. 

In short, Hopkins' possession margin allows the them to win 10-5 instead of 7-5.  It's that kind of situation.

DENVER

Possession Margin Per Game: 3.5 (12)
Face-Off Percentage: 57.97% (11)
Clearing Percentage: 85.42% (17)
Riding Percentage: 82.68% (34)

How is Denver Generating Possessions?

Not unlike Hopkins, the Pioneers are relying on the draw to generate offensive possessions.  Chase Carraro has been the engine for Denver, winning around 60% of his attempts on the season.  The Pioneers haven't been in the nation's elite creating possessions on the offensive and defensive clear -- especially on the ride -- so if they want to have the bean significantly more than their opponent, they need to do it from the "x."

Take a second to compare Denver's possession margin and Hopkins' possession margin.  The only large differences in pace-factor performance this season has been at the dot and generating possessions on the ride.  While these aren't huge percentage gaps, they end up resulting in almost three fewer possessions per game for the Pioneers' offense compared the Blue Jays' attack.

How Important is Denver's Possession Margin to Their Success?

I would say that it's very important.  The Pioneers are rolling with the most efficient offense in the country -- Denver is currently ranked first in adjusted offensive efficiency.  With guys like Mark Matthews and Alex Demopoulos, the Pioneers have cats that can generate tallies in all kinds of different ways.  Denver's offensive unit is the absolute strength of their team this year, and when that offense has an opportunity to get things going, the Pioneers are generally in good shape.

This isn't to say that the Denver defense is poor.  It isn't.  The Pioneers are currently 19th nationally in adjusted defensive efficiency.  It's just that when you're rolling with a freshman keeper, it's probably better to limit his exposure to shots and keep the ball in the crosse of a host of current and future All-Americans.

VIRGINIA

Possession Margin Per Game: 3.0 (15)
Face-Off Percentage: 50.52% (30)
Clearing Percentage: 91.10% (2)
Riding Percentage: 80.70% (16)

How is Virginia Generating Possessions?

The Cavaliers are a great example of a team that doesn't dominate the draw yet still carries a strong possession margin.  Where Virginia is really making its money is that their not giving away offensive opportunities, clearing at a ridiculous rate (only Syracuse has been better on the year). 

The other piece of the puzzle is a little more sublime: The Cavaliers are doing a good job on the ride and, as a result, are creating unsettled transition opportunities.  With these opportunities, Virginia is doing a strong job converting.  With the conversion, there isn't an immediate defensive possession that always follows; rather, play moves to the draw to establish a new set of possessions.  This is how the margin for the Cavaliers is ballooning.

How Important is Virginia's Possession Margin to Their Success?

Important but it's not absolutely vital.  The Cavaliers don't necessarily need to run a volume offense to generate tallies as they're seventh in the country in adjusted offensive efficiency.  They're putting the ball in the back of the net at a very efficient clip on a possession-basis.  Despite some of the knocks on the Cavaliers' defense this year, Virginia is still in the top-15 (11th, to be specific) in adjusted defensive efficiency.  So, the Cavaliers aren't going to yield tons of goals that their offense can't keep pace with if they end up playing more defensive possession per game than their opponent.

I think where Virginia finds value in their possession margin is in the style that they play.  The Cavaliers are the sixth-fastest team in the country and they really try to move at a quick pace.  When they're able to accelerate their clearing game and punish teams on the ride, they can really let their athletes move.  So, the possession margin, for Virginia, usually is a good indicator as to whether Virginia is playing a tempo that they prefer or not (and, as an aside, whether it's working effectively for them).

CORNELL

Possession Margin Per Game: 1.4 (25)
Face-Off Percentage: 46.23% (40)
Clearing Percentage: 85.96% (16)
Riding Percentage: 79.49% (10)

How is Cornell Generating Possessions?

Cornell is in almost the exact same situation as Virginia: The Big Red are getting possession margin value out of their ride.

How Important is Cornell's Possession Margin to Their Success?

To be honest, possession margin hasn't impacted Cornell's success all that much this year.  The Big Red are second in the nation in adjusted offensive efficiency and fourth in the country in adjusted defensive efficiency.  When you have an offense that converts at a really high rate when they actually do have the ball, you don't necessarily need a high possession margin because you're not running a volume offense.

The same holds true for Cornell's defense: Even though they're playing a really high number of defensive possessions per game (only 16 teams play more per game), the Big Red's unit as done a masterful job at keeping the ball out of the net.  The only time that possession margin becomes an issue is when Cornell's offense or defense has a tough time performing to the level that they're capable of.  This hasn't happened too often this year.