Which sensors should be used throughout the robot?

[thatprogrammer]

Originally Posted by Thad House

So the input shaft of the encoder is 1/4 inch. So its press fit in. Then teams zip tie the wires down, which stops the housing from spinning.

Okay, I thought you'd simply need to select the 1/4 inch diameter option for the encoders.
When would you use a high cpr vs a low cpr? It seems to me that using a high cpr encoder on a fly wheel might overwhelm the fpga. Any formula to figure out the max possible?

One last question: 971's mentor mentioned their robot featured:

"encoders with index pulses and used a potentiometer with those to resolve the integer number of revolution ambiguity."

How much % of error can one expect simply using an encoder rather than this set up? Is this set up really necessary or simply a practice that, while good for inspiration and education, is a bit overkill?
Thanks for all the help so far!