system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Trek] How much firepower can a Borgs individual shields handle?

How long would I have to phaser an adapted Borg until it's shields failed? How could a Borg have such powerful shields in such a small mobile unit?
gpt
First, understand that Borg shield design revolves around the principle of specific defense, as opposed to the conventional broad-spectrum defense.  When a Borg gets hit, it notifies the surrounding Drones that the enemy weapon is firing on a frequency of 123 hertz.  All Borg nearby shunt all their shield power into blocking that frequency.

Since all power is diverted to that frequency, it's dozens, if not hundreds of times more powerful than a conventional shield, which is trying to cover all possible frequencies.

Thus an attacker can fire until their power cell runs dry and never penetrate the Borg shield.

This does however, leave the Borg vulnerable to other frequencies.  A second attacker with a frequency of 321 hertz wouldn't encounter any resistance while firing.  
Since the Borg defense is concentrated against the first frequency, that means the second attack would bypass their shields entirely - as if they weren't even there.

But they'd only get one or two shots before the Borg identify the frequency and adapt to that too.  

Even blocking two specific frequencies still makes their shields impenetrable.  You'd need hundreds of weapons firing at different frequencies to burn through the personal shield.

It's much easier just to remodulate your phaser frequency every few shots in order to keep bypassing the shield.