I didn't say he won us the points. I said he contributed to the win. Without one save in particular - which he had no right to make - we may not have won. He was very good at Spurs. However, that has been the exception, not the rule. He isn't at Karius levels yet, but he's not a million miles away from him on current form and he is on a dangerous path.
One of his problems right now is that people are prepared to say "he cost us the points" when he blunders but are not prepared to say "he helped us win the points" on those increasingly rare occasions when he actually does. He hasn't actually cost us points this season, but it's only a matter of time on current trends. The team has bailed him out on a few occasions now. He needs to redress that balance starting in the derby.