A further criticism of this kind of jury selection is that it makes it easier to achieve a conviction, which critics argue leads to a higher chance of wrongful convictions. In most (if not all) jury systems a super-majority (or unanimity) is required to convict (e.g. in the UK over 83% of jurors are required for a conviction - a 10 to 2 majority can be accepted if a unanimous decision cannot be reached). If both sides are able to challenge jurors one would expect the prosecution to try to remove those with a general tendency to wish to acquit. Of course one would expect the defense to challenge those they think have a general tendency to convict, but if both sides do their job equally well then the tendency will be to turn what would have been a small majority (one way or the other) into a strong majority in the same direction, potentially causing the proportion to rise over the super-majority threshold required.