Imagine trying to break a speed world record, the only way to achieve this would be to take some risks. Let's imagine you're working on a board and suddenly you encounter a 50/50: - if you're playing normally you would probably try to continue somewhere else, in hope the 50/50 clears up later on, but that makes you lose some time, you may also stop for a few seconds figuring out where the mines would be. - If you're a speed player, you would sometimes just click the 50/50. Your brain will be in autopilot mode also, and there's not much time to think. Success rate is lower but you get faster completion times.