: Becker is a Hollywood type: a driven, sharp-as-a-tack intelligence devoted to a completely second-rate subject
[sharp as tacks is found by 1912]
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with sharp as a tack
sharp as a razor. Mentally acute. For example, She's very witty—she's sharp as a tack. These similes are also used literally to mean “having a keen cutting edge” and have largely replaced the earlier sharp as a needle or thorn. The first dates from about 1900, the variant from the mid-1800s.