Snowpacolypse 2011 has officially come and gone in my neck of the woods, which means it's time for another rousing edition of Stat Your Face Off. In case it wasn't already clear, our hope is that this series builds off the Statistics 101 series.
Standard Contradictory Disclaimer: It's all about exposure. I'm not saying all these stats are all super useful. Some are great. But some need work. You make that call. When/if you get into a stat fight though, I want you to be prepared, which is why I'm trying to expose y'all to everything that's out there. Sorta like Mr. Miyagi with all that "wax on ... wax off" nonsense. Ideally we'll all gain a better understanding of advanced statistics (their advantages and disadvantages).
Today we're taking a look at DYAR, or Defensive Yards Above Replacement. Join me after the jump if naked-eye player evaluation just isn't cutting it for ya.
Analogy Time!
While DVOA tries to break down a player's (or unit's) value-per-play, DYAR attempts to assess total value. I know we're all football fans here, but if you can, try to think of it like batting average versus RBI total. The former assesses likelihood (or amount) of success each play and the latter gauges the season-long contribution.
Here is the Football Outsiders explanation.
Critical Concept
One critical concept you have to grasp re: DYAR is "replacement level." Critics have questioned where this idea comes from. It is not team-specific, which can be tough to swallow since true "replacement level" is different for every team. For example, given the current roster, our true "replacement" RB if Turner ever goes down is Snelling. Not a bad alternative.
But imagine if Snelling got hurt, and then Turner got hurt a week or two later (knock on wood). At that point, our true "replacement" RB would be Gartrell Johnson. Not a good alternative. There's a big difference between Johnson and Snelling. To account for this never-ending fluctuation between teams, the downright kooky hardworking folks at Football Outsiders have created (and subsequently tweaked) position-specific replacement levels.
Calculation
There's no readily-available formula that calculates DYAR. But here's how they calculate it for QBs:
[W]e analyzed situations where two or more quarterbacks had played meaningful snaps for a team in the same season, then compared the overall DVOA of the original starters to the overall DVOA of the replacements. We did not include situations where the backup was actually a top prospect waiting his turn on the bench, since a first-round pick is by no means a "replacement-level" player.
And here's how they calculate it for WRs/RBs/TEs:
At other positions, there is no easy way to separate players into "starters" and "replacements," since unlike at quarterback, being the starter doesn't make you the only guy who gets in the game. Instead, we used a simpler method, ranking players at each position in each season by attempts. The players who made up the final 10 percent of passes or runs were split out as "replacement players" and then compared to the players making up the other 90 percent of plays at that position.
2010 DYARs
RBs:
Turner - 99 or 17/45 (minimum 100 rushes)
Snelling - 15 (did not have minimum rushes required for ranking)
WRs:
White - 294 or 4/85 WRs (minimum 50 passes)
Jenkins - 107 or 46/85 WRs
Douglas - negative 59 or 77/85 WRs
Finneran - 23 (did not have minimum passes required for ranking)
TEs:
Gonzalez - 72 or 21/45 TEs (minimum 25 passes)
Peelle - 20 (did not have minimum passes required for ranking)
And last but not least, Matty Ice's DYAR this year was 1,350 (6/46 QBs with minimum of 100 passes). Brady had the highest DYAR (2,141 or 1/46) and Clausen had the lowest DYAR (-607 or 46/46).
In case you couldn't tell, I'm not entirely sold on DYAR. With time though, they'll discover a better way to devise replacement-level, and that will go a long way towards augmenting this stat's user-friendliness. But what say you?! Like it, love it, or hate it: I want to hear your thoughts. And as always, GO FORTH AND BE STATISTICAL!