The balk field guide
Every way a pitcher can balk.
A balk is one of baseball's most misunderstood infractions — partly because the wording changes depending on which rule book you play under. This site documents each balk once, then shows how the OBR, NCAA, and NFHS rule books phrase it, with the exact rule number and video examples.
Pick a rule set
Official Baseball Rules
The Official Baseball Rules govern professional baseball and are the default rule set for most games played around the world.
Browse OBR balks →NCAA Baseball Rules
The NCAA Baseball rules govern collegiate play in the United States. Their pitching and balk provisions closely track OBR, with a handful of wording differences and a few college-specific wrinkles.
Browse NCAA balks →NFHS Baseball Rules
The National Federation of State High School Associations (NFHS) governs high school baseball in the United States. Its pitching rules differ substantially from OBR — most notably in how the set and windup positions are defined — so balks that look identical on the field are often written very differently in the NFHS book.
Browse NFHS balks →