# Where can I shoot from on the field?

We’re trying to figure out where the robot can shoot high goals from on the field in the current game. We’re trying to perfect our accuracy for the game and we’re having trouble in the case of seeing how close or far we need to go to be as accurate as possible. Can anyone please provide some dimensions to help with this issue?

Pretty much anywhere that isn’t the opposite alliance sector

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I don’t think the question was about legality, but about dimensions to model trajectory calculation. The center of the inner port is 8.0 ft off the ground.

1. This is a question you should have been asking about 3 weeks ago.
2. The dimensions of every field element are in the manual, if that’s what you’re looking for.
1. The #openalliance all posted a ton of strategic analysis back in week 1. Go check out their build threads.
2. “What’s the highest accuracy shot” is a complicated question, and it depends on a lot of factors. This is a trajectory calculator that tries to help you get your most accurate shot. Taking a different approach, the target will have a different Angular Size from different distances and initial heights. From right next to the wall looking up at the outer port, the opening is going to look like a little sliver. As you back up, it’s going to look larger and larger, up to a point where your distance from the goal starts to make it look smaller again. While angular size isn’t a perfect way to judge your accuracy, it’s probably not a bad way to make an estimate. The distance from the wall where the goal has the largest angular size changes based on how tall your robot is. If you just want someone to tell you where to shoot from, then here’s a guesstimate:
Short Robots (shooter ~24" off the ground) should shoot from 52 inches for the outer port, or 142 for the inner port.
Tall Robots (shooter ~40" off the ground) should shoot from 40 inches for the outer port, or 106 for the inner port.

For a real answer, go build a robot, put it at different distances, and see where you shoot best from.

Edit: updated numbers. I was using 2D degrees previously instead of degrees^2.

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Shoot up against hardstops on the field - it makes alignment much easier and will provide a limited amount of protection from defense. Examples from previous years include shooting up against the low goal box in 2014 and the batter shot from 2016 up against the tower. Where those hardstops are this year and which are the most ideal to shoot from is up to you to find out.

It seems to be both, actually. The answer given is correct from a legality perspective.

@bluesteel, what dimensions do you need? And are they found in either the Manual, Section 3 or in the Field Drawings, particularly the Layout drawings?

I have to concur with @BordomBeThyName’s first point. My team tested a mockup shooter from near max range a full week ago.

To answer this question from a non-legality standpoint.

We can use math and a couple assumptions to get the accuracy at any given point on the field. The following walk through will using the following assumptions:

1. You are taking a linear shot.
2. The outer goal is actually a circle inscribed inside the given hexagon.

(I will leave this problem without the above assumed as something to the reader)

Let P be the path of the ball. We know to make an inner goal, P must intersect the center of the inner goal. Also, P must intersect the outer goal (assumed to be a circle). Thus, the set of all P form a cone.

We set S be the plane of the shooter. S is a plane that is parallel to the plane of the floor containing where the point where you are shooting from. This is specifically where the ball exits the shooter (or other mechanism).
The cone S and plane P create a conic section that creates a hyperbola of everywhere a robot can take a 3 point shot. This can be plotted in a program like trinket.io or desmos.
Once you know everywhere you can shoot, you can use the vectors from the shooter to either side of the target to find the tolerance of your shot. The higher tolerance the better shot you have.

The above is by no way complete, but it should hopefully give people direction into finding the most accurate places to shoot from.

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