At what rating does the Fried Liver stop working?


As an easy way to win with opening traps, expect it to stop working at around 1200. As a known viable opening for both sides, it still works, as already mentioned.

Many seem to have a misconception about what the Fried Liver Attack is. It does not start with 4. Ng5. It starts with a Knight sac on f7 in this line:
Black can easily avoid it by simply not playing 5...Nxd5. I'd say you'll hardly find anyone above 1400-1500 playing into the Fried Liver.
By the way, the Fried Liver may not even be the best response against 5...Nxd5. The Lolli Attack 6.d4 is probably preferable.