Welcome to the VEX Robotics Competition
Referee Training Videos,
designed for both referees and teams.
This is Chapter Five: Trapping.
Trapping rules, or what used to be
called "pinning" rules,
can often be sources of confusion
for referees and teams.
They can be some of the more
subjective calls.
And it's difficult to categorize
every possible type of
robot-on-robot interaction.
So the examples and explanations
given in this video should help
teams and referees to develop
a better idea of what trapping is
and what it is not.
But again, it's impossible to cover
ALL scenarios,
so there will be some
judgment calls involved.
Let's begin with the relevant definition
Direct trapping is what used to be
called "pinning".
A robot holding another robot
against a field element,
such as a wall or Tower,
and preventing them from getting away.
However, trapping can also be indirect
and can be just as effective.
This robot is effectively restricted
to a small area of the field
but without the aggressive contact
associated with a traditional pin.
A "small area" in this case
is considered one foam tile or less.
Remember, a robot does not actually
have to be contacting its opponent
for trapping to occur,
so long as the opponent cannot break out
of the confined area
and play the rest of the match.
Tower Takeover is the first game
in a while to not have an
expansion limit,
so we may see extremely wide robots,
sometimes called "wall-bots".
If they're being driven correctly,
wall-bots are normally not in violation
of trapping,
as they typically are not restricting
opposing robots to a small area
of the field.
Also, in all forms of Trapping,
there is a responsibility on the part
of the robot being Trapped
to make a visible and active effort
towards breaking free.
Simply sitting still will not result
in a trapping violation.
In VRC Tower Takeover,
the corners of the field are where
a lot of crucial moments in the match
are going to happen!
So if a robot is near one of their own
goal zones, with an opponent strafing
side-to-side behind them,
referees will need to ask themselves:
Is the offensive robot
intending to be there?
Or are they actively trying to get out?
If they're in the act of scoring,
they're probably not trying to get out,
and it's probably not a trapping call.
Now, let's take a look at rule ,
which explains how pinning and trapping
should be handled during a match.
Once a referee has identified that
trapping has begun,
they should immediately provide a
clear verbal and visual cue
to all teams that a count has begun.
This means you should use your hand
to count, gesture to the violation,
if possible,
and count loudly and clearly.
When teams notice a referee
counting down,
they'll usually back off a lot sooner
than the full five seconds,
and the count effectively ends up
acting as a warning to all teams.
Also, it's important for referees to
be assertive when calling for a
trapping count.
Referees are sometimes hesitant
to start counting until after the trap
has already been clearly established,
which can actually turn a five second
count into eight or nine seconds of
actual trapping.
This is one of the most common sources
of frustration for teams
and new referees.
A direct Trap,
often refered to as a pin,
should be easy to identify.
Watch for a robot stuck between a
field element and an opponent robot,
not moving.
An indirect trap may be more difficult
to identify, but is still
just as important to watch for.
So, if you see a robot stuck
in a particular area,
with a wall-bot or an opponent
strafing side-to-side in front of them,
they are probably being Trapped.
If you're still not sure,
a verbal warning, such as
"Let them out of there!"
is a good start.
The next section of the rule states:
There should be no confusion that the
offending team has either not satisfied
their five seconds of backing away
or has not backed away far enough.
This is a very commonly misunderstood
part of the call.
If you wait for the aggressor to
back a full field tile away
before even stopping the count,
there should be no confusion.
Then, once you've stopped the count,
take a mental note of the time
on the field timer,
and keep an eye on the aggressor.
Defensive teams will often ride
the very edge of this limit,
which is legal
but only if they wait the
full five seconds
and only if they move the
full field tile away.
Now, there are two other subtle details
regarding trapping
that are worth mentioning.
First, if an opposing robot blocks
a team from moving away and
breaking a pin,
then the count can be ended.
This robot sandwich is related to ,
which states that
In this interpretation,
you cannot force a robot
to trap another robot.
And lastly,
but sometimes most importantly,
if your robot stops working
for any reason,
you're still responsible
for its actions.
This means that if you're
in the act of trapping,
lose control of your robot,
and your opponent is still unable
to break free,
then a trapping count of violation
would still occur.
That being said,
the opposite is also true.
If your robot malfunctions
while you're being trapped,
and you stop trying to escape,
then the count will stop.
This could mean a dead battery,
an overheated motor,
even a radio disconnect.
In any case, your robot is no longer
actively trying to break free.
It would be silly to penalize someone
for trapping a robot that can't move!
Sometimes when a trapping count occurs,
drivers will try and show the referee
that they're not touching their controls
This is actually counter to the
definition of trapping,
as we just explained.
If you're the one being trapped,
and you're not touching the controls,
then you're essentially telling the
referee to stop counting
because you're no longer trying
to break free.
On the other hand, if you're
the one doing the trapping,
it doesn't matter whether you're
touching your controls or not
because you're still responsible for
the actions of your own robot.
Trapping can be one of the
most difficult calls to make in the
VEX Robotics Competition,
but it is absolutely necessary to ensure
a fair and offensive game.
As such, referees need to be
vigilant and confident
when watching for these violation.
They also need to clearly communicate
when warning teams and counting out loud
to deter potential violations.
That's all for Chapter Five,
so thanks for watching.
And be sure to check out
the other chapters in this
Referee Training Series
on other specific refereeing topics.