Van

• Same eraDarwinLike Van, it was given most in the 1950s.#960 · steady
• Same rhythmGageSame beat as Van: one syllable, ending on a consonant, but it starts differently.#973 · falling
• LongerHarlemTwo syllables to Van's one: a long name beside a short one keeps them distinct.#970 · steady
• RiskyIanOne letter away from Van. You'll call the wrong one for years.#83 · steady

Suggestions come from names in this year's top 1,000. Rhythm and rhyme are judged from each name's pronunciation (Wiktionary's, or espeak's reading of the spelling), so a few calls may be off.