Just got one of my friends to do it, he split the £10 evenly between red and black because he wanted to be almost guaranteed to win £10 instead of having a 50% chance at £20. It landed on green lol.
I'm pretty sure that it's a coincidence that he was the first person to try that and he didn't win, but if anyone else has tried the same and had the same happen to them please post itt
Thanks.