Episode 167 - Bingo Hacks

Bally Bingos were big money.  If the machines had a feature that allowed for skilled players to earn replays too quickly, some sly operators would disable that feature.  Alternatively, they might make it come up much less frequently.
Working on a hacked game can be difficult - some of the technicians were very clever.  The ham-fisted ones are usually very obvious and easy to repair.