Captcha Sniper 5.17

What capchas to use with NHS? Before there where numbers which made it easy. Now it seems to be a very high fail rate even on captchas that should be solved (since they're pretty basic).
Any ideas? I know there are old posts regarding this topic but those ... well ... are old and not really up to date.
Any ideas? I know there are old posts regarding this topic but those ... well ... are old and not really up to date.