Monday, September 24, 2012

The Patient Offense and the Spirit of the Rules

There's a lot of talk going on about rules changes and "stroller derby."  People are throwing out all sorts of radical ideas for new rules that would massively alter the game of flat track roller derby.  I usually ignore the gnashing of teeth.  I happen to think the rule set that WFTDA plays under is, for the most part, pretty damn good.  It's led to explosive growth for the sport, and I think drastically changing the rules by removing power jams or something extreme like that would be fixing what isn’t broken.  Still, the current WFTDA rule set is not perfect.  It’s definitely a work in progress.  People just need to realize that it needs to be honed, not rebuilt.

“Slow derby sucks!” is a familiar battle cry.  —But different people define different strategies as slow derby.  For me, slow derby used to always refer to the no/slow starts where the pack would just hang out behind the pivot line and the jammers would never be released.  That issue has largely been solved by counter-strategies like knee starting.  Other people hear “slow derby” and think of scrum starts.  I personally love scrum starts because I love seeing blockers engaging the jammer and working together.  Scrums are, by definition, engaging roller derby.  They just start off with slow-moving engagement.

When I think of slow derby today, I’m thinking about the patient offense/pace line strategy.  I hate, hate, hate this kind of roller derby.  I understand that it’s effective.  I understand that teams who want to win feel like they have to use this tactic in order to win important bouts.  They train really hard all year long to try and win, so why wouldn’t they do everything they can to win even if it means boos and alienating fans?  I get that.  It’s just a terrible abuse of the rules, and it's bad for the sport as a whole.

Let’s break this strategy down for a second and look at how the patient offense is taking advantage of a loophole.  The Springfield Isotopes jammer is sent to the penalty box giving the Shelbyville Maulers a power jam.  The Maulers choose to skate as slowly as possible on the outside line to try and convert the power jam into as many points as possible.  The rules do not say the pack has to maintain any specific speed.  All they say is that once the pack is in motion, the pace is set.  The blockers must stay within the bounds of the pack at whatever pace it is moving.

A pack that is moving at a quarter of a mile per hour is set at that pace and perfectly legal.  Once the pace of the pack is set at 0.25 mph, there is almost nothing that the Isotopes can do to speed it up.  The Maulers jammer engages the pack, and the Isotopes block her until there is a 10-foot gap between the teams, resulting in no pack and 5 points for the Maulers.  The rules require that both teams reform the pack, but once the teams are back within 10 feet of each other, the Maulers can just maintain a 9-foot gap (skating backwards if necessary), and thus force another quick no-pack and get another 5 points without doing much of anything.  Rinse and repeat.  Over and over.

The problem with this strategy is that it’s a tactic employed intentionally to destroy the pack.  Let me repeat that.  Pace line derby is intentional destruction of the pack.  I don't think anyone can argue this.  It may not be an active act of destroying the pack, but it is definitely a passive act of destroying the pack.

Let’s look at what the current WFTDA rules have to say about maintaining a pack:

4.1.2 - When two or more groups of Blockers equal in number are on the track; are more than 10 feet from one another; and no single group meets the pack definition, no pack can be defined. Skaters will be issued a penalty for intentionally creating a no pack situation i.e. destroying the pack (see Section 6.10.2). Both teams are responsible for maintaining a legally defined pack. A skater or group of skaters is always responsible for the consequences of their actions. If their actions create a no pack situation (except those covered in Section, they should be penalized as directed in Sections 6.10.9–6.10.24.

There’s the problem.  The rules state that both reams are responsible for maintaining a pack, but they only penalize “actions” that result in a no pack situation.  They do not say anything about inaction that results in a no pack situation.  Inaction which results in destruction of the pack may not be against the letter of the rules, but it is most definitely against the spirit of the rules.

So how is the patient offense any different than stopping altogether or just dropping to a knee?  It's not.  The patient offense is minimal movement which results in destruction of the pack.  It’s just that the current rules surrounding destroying the pack do not include instances where a team maintains an extremely slow pace to intentionally force a no pack situation.  There's a loophole allowing teams to intentionally destroy the pack without being penalized for it.

A lot of people want to overhaul the rules and define the pack as the group of blockers in the front... or include jammers as part of the pack... or something game-changing like that.  I would prefer WFTDA not use a sledgehammer and instead use a scalpel.  The simplest solution is to just close the loophole and define pace line derby as illegal destruction of the pack.  It’s the responsibility of both teams to maintain the pack, right?  Why not enforce that?  Referees already require skaters reform the pack when no pack exists.  Would it not also make sense to have referees require skaters to make an effort to maintain the pack?  I think that's perfectly reasonable, and it wouldn't really change the way roller derby is played.

Now let’s take a look at the current WFTDA rules regarding destruction of the pack: - Examples of illegally destroying the pack, or creating a “no pack” situation, may include but are not limited to: a skater, skaters or team running away, braking or coasting to drop back more than ten (10) feet behind the opposing team, taking a knee, intentionally falling, or intentionally skating out of bounds in such a manner that the legally defined pack is destroyed. - The rules do not define pack speed. Illegally destroying the pack penalties shall not be given for gradually deviating from the speed of the pack as established through game play, unless said deviation is sudden, rapid and marked, leaving the opposing team no opportunity to adjust and maintain a pack.

I highlighted the part about leaving no opportunity for the opposing team to maintain the pack here because that’s exactly what pace line derby does.  If the Isotopes blockers try to skate backwards to close the 9-foot gap and allow themselves a chance to engage the jammer while maintaining the pack, the Maulers will just skate backwards as well in order to maintain the 9-foot gap.  The idea is to basically keep the Isotopes on the edge of a cliff so that if they try to block the jammer, they end up destroying the pack and have to let her go anyway.  The pace line tactic is successful in that it leaves the opposing team no opportunity to both engage the jammer (play roller derby) and maintain the pack.  They have to choose one and not the other, which leaves the Isotopes blockers helpless and results in the Maulers racking up grand slams with little-to-no effort.

Section could simply be amended to include something like “inaction such as minimal movement which causes the natural continuation of play to result in a no pack situation” as an example of illegally destroying the pack.  It seems pretty simple to me.  If the rules included something like this, the Maulers would be compelled to engage the pack and try to trap an Isotopes blocker.

Regardless of how it’s worded, I really hope that this kind of rule change is enacted.  I know this isn’t a perfect solution, there may be no perfect solution, but I think it’s very important that WFTDA does something to incent teams to actively play roller derby.  Most of the time, I’m fine with letting counter-strategies develop to progress the sport.  I just happen to think that there are no real counter-strategies that can be developed to correct this quirk in the rules.  The patient offense is a great example of loophole exploitation, and in my opinion, the loophole just needs to be closed.

Tuesday, September 18, 2012

Jams Fielded Per Penalty Turn

Any educated fan can tell you that penalties are huge in roller derby.  If you read my stats study earlier this year on Queen of the Rink, then you have a pretty good idea of just how big they can be.  —And it seems like the effect that penalties have on the game is getting larger.  As teams begin to get closer in skill level and strategies continue to advance, losing skaters to the penalty box becomes more and more hindering.

Because of this, there is also an increased need for good penalty management tools.  I had experimented with some penalty frequency statistics like "minors per jam" [(majors × 4 + minors) / jams], but I was never satisfied with the usefulness of something like that.  I've seen other statistics like fractional penalty minutes that attempt to factor in the impact of minors to scale with majors, but again, those kinds of statistics are not very useful because of the difficulty in comprehending them.  In my opinion, a stat is only as useful as it is understandable.

One of the big problems is measuring penalty frequency by jams skated.  Jams skated is a good divisor in basic roller derby stats like points per jam or lead jam percentage.  It can give you useful averages for a lot of things, but not for penalty frequency.  The reason for this is because with penalty frequency statistics, serving a penalty turn can actually help a player's rating.

To illustrate what I'm talking about, let's look at 2 skaters who commit the same penalty.  Fannie Flash goes into the penalty box at the beginning of a jam and exits later in the same jam.  She skates in 1 jam and gets 1 major penalty.  That's a 1:1 ratio of penalties:jams skated.  In the next jam Rascal Rae goes to the penalty box for committing the same penalty, but the jam is called off shortly after she sits down.  Another jam passes, and then Rascal Rae exits the penalty box in a third jam.  In this case, the ratio of penalties:jams skated would be 1:3.  The problem is that Fannie and Rascal commit penalties at the same frequency.  Fannie had no control over the jam continuing and Rascal had no control over being in 2 more jams.  Using jams skated for penalty frequency statistics is unreliable.

The real question at hand is: "How often do skaters go to the penalty box when you send them into the game?"  The number of jams a skater is actually in is irrelevant.  If you subtract the number of times a skater begins the jam in the penalty box, from the number of jams she was in, you'll get the actual number times she was sent onto the track.  —Something I like to call Jams Fielded.  Hopefully, your lineup trackers are recording when skters enter and exit the penalty box.  If they do, this should be an easy stat to calculate.

Using Jams Fielded can really highlight how often skaters are actually sent onto the track and how often skaters just end up in the penalty box, stuck in the game for another jam.  Once you divide the jams fielded by the number of penalty turns a skater has incurred, you'll get the average number of times a skater is fielded before she goes to the penalty box.  This is the Jams Fielded Per Penalty Turn.  I love this stat because it's very simple to read.  A score of 6.25 means that every 6.25 times a skater has been sent into a jam, that skater has gone to the penalty box.  It's simple; the higher the score, the better.

So, how is this useful?  Well, obviously it's very useful to know how penalty prone every skater has been.  Keep in mind, though that you also have to take into account how active the skater is in the pack.  A skater who is an actively hitting blocker (doing the heavy lifting in the pack) is simply going to garner more penalties than a skater who usually just positionally blocks.  Still, it can be really helpful to know when you only have 2 blockers on the track because in that situation, you're need to get your team out of the penalty box carousel of doom.  Maybe in stead of putting in you 2 strongest blockers, you might want to put out a couple of clean blockers for a jam to try and get back to a 3-pack or a 4-pack for the following jam.  Sure they might not be as strong as other blockers, but sometimes losing a jam or two can be worth it if you are stronger in the pack for several jams afterwards.

Also, I highly recommend splitting this stat between jammer and blocker statistics (keep in mind that any poodling jammer is going to have a bad blocker score).  Obviously, it's far more important to have a clean jammer than a clean blocker.  One or two power jams is often the difference in winning or losing a bout.  If you can put together a clean jamming rotation, it can be a huge advantage.

In the end, this is all about managing penalties.  Your average 60-minute bout is going to be approximately 40-42 jams.  You can use Jams Fielded Per Penalty Turn to get an idea of how many penalties to expect from blockers team based on your lines.  You can use it to help predict the number of power jams you are likely to surrender based on your jamming rotation.  Sometimes just knowing what to expect ahead of time can help a team keep their heads and avoid compoinding penalties.  There are a lot of ways you can apply Jams Fielded Per Penalty Turn to help manage the game and give your team the best chance at winning.