Somehow people tend to do " unmotivated" triggers.
Trigger itself should be an event we can measure or rely upon. For event to be qualified as a trigger , it has to posses sertain qualities:
1. Being logically motivated.
Bird farts in other continent are definitely affect roulette outcome on where you play, buy no reliable way to measure them or correlate to final result.
2. Being statistically significant.
Whatever your trigger is, it has to correlate to ball behavior or final result by the degree wich is beyond the doubt.
3. Being consistent in its affect of outcome.
Need to form hypotesis priory or based on data collected previously, to verify trigger in future data taken. Easiest way to test your triggers is to separate your sample in many samples and crossest them... bigger part could be used for hypotesis formation and smaller for testing. There are lots of possibilities.
4. Being not random. Need to verify if other situations in game can produce same or similar result without relying on your trigger.
If all of these conditions satisfied, congratulations!!! You got yourself a trigger