Difference between Cut someone off and Cut someone off at the pass

cut someone off—

1. (also: cut someone off short) interrupt a person:

• The doctor came in and started to explain the procedure, but I cut him off.

2. (usually Passive) isolate or separate a person (from smth.):

• We were cut off by the incoming sea and nearly drowned.

3. (usually Passive) kill a person:

• Mary was gone, cut off in the prime of life, in the glow of beauty.

cut someone off at the pass—

1. intercept a person:

• When I noticed he was leaving I figured I would cut him off at the pass and have him sign an autograph.

2. foil smb.’s plans or efforts:

• The good guys intend to blow up a fort. Will they succeed or be cut off at the pass?