I found some claim that you need to deposit an amount greater than or equal to the free rolls amount you have won so far. Other say that you don't actually need to deposit, as long as your balance is greater than or equal to double the free rolls amount you have accumulated. (you can see this info in Stats -> Personal Stats in your account.)
Is anyone aware of any official statement about this, or is everyone just speculating?
Yes, I asked about it when it changed a while back and Wetsuit the site owner replied telling us of the 2x free rolls total requirement. There is a certain amount of multiply BTC and/or Lottery tickets purchased needed as well, I'm not sure what exactly the requirement is but I haven't done either for quite a long time and I don't get a captcha.
The amount isn't the same for everyone. If your balance is equal to or greater than 2x of your total free play winnings, you do not need to solve a captcha.
Ahh, that's why it came back, you changed it from playing hi/lo game. Looks like I'm stuck with capture then as I've been playing for so long.
Also, wagering in the HI-LO game helps. I had to increase the balance requirements to 2x from 1x previously because botters had figured it out and could reach no-captcha without depositing. Now they will need to deposit to roll without captcha so it has reduced their activity.