THE JAMMER QUOTIENT EXPLAINED
Since I began to watch roller derby, I’d always wondered where the stats were. From what I could tell the leagues made a huge effort to record data—all those people sitting in the centre of the track and around the penalty box pens in hands—but as a fan I wasn’t seeing them. And since roller derby is a relatively new sport (particularly in its flat track form), and I new to it, I didn’t even know which stats were important and worth following. The Derby Nerd went to work.
Every major sports league finds some way to statistically compare its players, and I wanted some way to do the same with roller derby. The JQ is the best way I could think of to compare jammers, who have the most visible role on the track.* The JQ is a statistical comparison of jammers based on their rankings in five categories. Here are the the JQ Ratings for the February 27th,2010,CN Power (199) and Rideau Valley Vixens (49) bout at The Hangar.
|Jammer||Total Points||Points Per Jam||Plus/ Minus||Jam %||Lead %||JQ|
|Lunchbox (CNP)||48 (9)||4.36 (9)||+36 (9)||23.4 (8)||72.7 (9)||44|
|Land Shark CNP)||53 (10)||3.78 (7)||+45 (10)||29.7 (9)||57.1 (7)||43|
|Defecaitlin (CNP)||45 (8)||4.5 (10)||+29 (8)||21.2 (6)||70 (8)||40|
|Marvel S. Maven (CNP)||25 (7)||4.16 (8)||+20 (7)||12.7 (3)||100 (10)||35|
|Soul Rekker (RVV)||19 (6)||1.18 (4)||-35 (5)||34 (10)||50 (6)||31|
Below is a breakdown of the five categories used to determine the total JQ (only the top five in each category are shown). For a condensed explanation, check here.
|Land Shark (CNP)||53 (10)|
|Lunchbox (CNP)||48 (9)|
|Defecaitlin (CNP)||45 (8)|
|Marvel S. Maven (CNP)||25 (7)|
|Soul Rekker (RVV)||19 (6)|
When all is said and done, most points always wins. There’s no way any analysis of jammers could exclude this. Land Shark was the workhorse for CN Power putting up a remarkable 53 points.
Points Per Jam
|Jammer||Points Per Jam|
|Defecaitlin (CNP)||4.5 (10)|
|Lunchbox (CNP)||4.36 (9)|
|Marvel S. Maven (CNP)||4.16 (8)|
|Land Shark (CNP)||3.78 (7)|
|Sister Disaster (RVV)||1.57 (6)|
Points per jam is also an important indicator of a jammer’s value, particularly in situations where a team might need a guaranteed score, or if the opposing team’s jammer is in the penalty box and a team wants to be sure to put up a lot of points. Defecaitlin may not have been as busy as Lunch Box or Land Shark (jamming anyway; she did her share of mixing it up in the pack too), but she made the most of her jams, gaining well over a full score (4 points) each jam.
|Land Shark (CNP)||+45 (10)|
|Lunchbox (CNP)||+36 (9)|
|Defecaitlin (CNP)||+29 (8)|
|Marvel S. Maven (CNP)||+20 (7)|
|Ripper A Part (RVV)||-25 (6)|
The last of the pure points categories is the plus/minus. A jammer’s plus/minus indicates the difference between the amount of points a jammer scores and the amount of points the opposing jammer scores against her. This is a good indicator of how well aware a jammer is of the other players on the track at all times. Land Shark (and the other CN Power jammers) dominated in this category as well.
|Soul Rekker (RVV)||34 (10)|
|Land Shark (CNP)||29.7 (9)|
|Lunchbox (CNP)||23.4 (8)|
|Ripper A Part (RVV)||23.4 (8)|
|Defecaitlin (CNP)||21.2 (6)|
The jam percentage represents the percentage of a team’s jams that a jammer does. This is the only category that has two members of the Vixens in the top 5. Soul Rekker really stepped up for the overmatched Vixens and wore the panty every third jam for both halves, a truly remarkable performance.
|Marvel S. Maven (CNP)||100 (10)|
|Lunchbox (CNP)||72.7 (9)|
|Defecaitlin (CNP)||70 (8)|
|Land Shark (CNP)||57.1 (7)|
|Soul Rekker (RVV)||50 (6)|
The final category, the lead percentage, represents the percentage of a jammer’s jams in which she wins lead jammer. Marvel S. Maven made the most out of all the jams she got, never giving up the star on any of them. It’s interesting to note that Land Shark and Soul Rekker, who did the most jamming for each of their teams, and often against each other, had lower jam percentages. I suspect that patterns such as this (and the match ups they represent) will be most evident in the final two categories.
I’m looking forward to applying the JQ over ToRD’s full 2010 season.
Just a note: There’s a ToRD “Fan’s Choice” scrimmage this weekend that should be a lot of fun. The first fans who arrive get to choose which players are on which team. Word around the track is that there will be guests from other leagues including some fan favourites from Forest City.
(*A similar comparison could be done with blocker stats too, and I’ll start working on that soon).