We knew somebody who worked at Sheffield dogs. It wouldn't be an exaggeration to say that the sport is corrupt as fuck and when one of the dogs we'd bet on won by about 14 lengths and we'd gone big on it, my stakes were limited to 10p. Coral banned me for (an honest) winning bet on Serena Williams winning a set 6-1 and I can't remember which other one banned me - that was when Yeovil beat somebody in the last minute when their opponents had had a couple of goalkeepers sent off. I used to get some "interesting" information / tips. The guy I got them from developed a gambling addiction, lost tens of thousand of pounds and then we lost contact.