That's the answer to your description's question: before or on the 51st ball drawn. But since your heading asks a slightly different question, I'll also answer your heading's question, which is just before 51 balls.
Looking for the definition of AFIS? Find out what is the full meaning of AFIS on Abbreviations.com! 'Automated Fingerprint Identification System' is one option -- get in to view more @ The Web's largest and most authoritative acronyms and abbreviations resource.
Breakers designed to protect against parallel arcs are called Arc-Fault Circuit Breakers, have a suffix AFI, and have a green test button (early versions had a blue button). An example catalog number is QO120AFI. CAFI - Combination Arc-Fault Circuit Breakers (protection against over loads, short circuit, parallel arcing, and series arcing) Breakers with CAFI suffix provide standard thermal/magnetic protection, PLUS protection against heat damage caused by parallel AND SERIES arcing in the circuit.