|Analysis of Division I Menís Lacrosse Statistics|
|By Michael Mauboussin|
Defense is the mirror image of offense. The task is to minimize the combination of shots per game and shooting percentage. The best defensive teams Ė think Notre Dame, Johns Hopkins, and Syracuse in 2011 Ė hold opponents to below-average shots per game and below average shooting percentage.
Exhibit 7 starts shows the correlation between shots yielded per game and goals against per game. An opposing teamís ability to score starts with its ability to shoot. The statistics of shots yielded is also related to possession frequency and time of possession. Because college lacrosse does not (yet) have a shot clock, and stall warnings come at the discretion of the referees, one team can limit its opponentís possessions by sustaining long possessions itself and by being careful to minimize turnovers and violations.
The second main driver of defense is shooting percentage yielded, i.e., what percent of the shots by the opposing team score. Exhibit 8 shows that this ratio also correlates strongly with goals allowed per game.
Caused Turnovers. One statistic that is some observers associate with good defense is caused turnovers. As noted earlier, there are about eight caused turnovers per game in Division I lacrosse. However, there is no correlation between caused turnovers per game and goals allowed per game. Indeed, some of the very best defensive teams have among the lowest caused turnover totals. For example, the leader in Division I scoring defense, Hofstra, averaged only 5.7 caused turnovers per game and the number two defense, Notre Dame, averaged just 6.6.
Penalties. The majority of penalties are called when the opposing team has the ball. There are on average four penalties called on each team per game. The team with the extra man scores about 31 percent of the time, a substantial (30-50 percent) increase in the scoring rate versus a matchup of even strength. This analysis doesnít distinguish between technical fouls (30 seconds) and personal fouls (60 to 180 seconds), although it stands to reason that that percentage of success rises meaningfully with longer penalties.
Save Percentage. The average save percentage (saves/(saves + goals scored)) for goalies is 52 percent with a standard deviation of 4. Save percentage correlates reasonably well with goals allowed per game, as Exhibit 9 shows. The causality is hard to sort out in this case, that is, whether the defense is good because of the goalie or the goalie is good because of the defense. Certainly causality runs both ways.
Further, goalies should be evaluated on the three skills that they require to add value. First, the goalie is central to good team defense because he is the prime coordinator and communicator. Second, the goalie must make stops. And finally, goalies are crucial to the clearing game. Goalies who can quickly and accurately move the ball down field are a tremendous asset in the transition game.
Endnotes can be found at the bottom of Part 5. Appendix A appears in Part 6, and Appendices B and C are presented in Part 7.
Michael Mauboussin works an as investment strategist. He is a lacrosse fan, youth coach, and retired player. For more, see www.michaelmauboussin.com.
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