SAN FRANCISCO — Draymond Green, the second-rounder turned four-time NBA champion, tends to root for the underdog.

Imagine his delight in meeting a room full of autistic people, a crowd that has been underestimated, misunderstood, even outright ridiculed.

At an event in advance of Tuesday’s Autism Acceptance Night at Chase Center, the four-time Golden State All-Star delivered what essentially was a two-hour pep talk last week. At the California Academy of Sciences, where Green kept things lively with nonstop monologue, he capped things off by telling the youth in attendance to ignore the doubters, as he once did.