I'm certain he had a decent early record for us (if we count opposition misses here)
Then it kinda got horrible where he wouldn't save any at all for like five years
Then he got a few towards the end which improved the ratio.
It’s not the easiest comparison to make as you face different players and the setting is also situational, easier to take a penalty in a league match rather than crucial penalties in big competitions. Then there are the stats behind it, don’t remember the last knockout where this was demonstrated, world cup perhaps?, where you could see the goalkeeper studying the notes of where the opposition player is most likely to place his penalty. De Gea used to get a lot of criticism for rarely jumping the right way, but it’s usually a decision based on stats so it’s a bit of an unfair stick to beat someone with. There are very few goalkeepers that put doubt into the oppositional player when it comes to penalties, if the penalty is well placed and struck with a bit of power then it’s very rarely, if ever, going to get saved.
Then again, i also think that people are way too harsh when it comes to what is defined as a mistake by the goalkeeper. People rarely take into account how the goalkeeper is positioned with his feet when the shot is taken, and how fast the ball actually comes at the goalkeeper and distance. Plenty of shots from close range and closely towards the goalkeepers body makes it very awkward to save depending on height.
Taking advantage of Onana’s strengths in terms of being comfortable on the ball depends on the rest of the players, as a lot of his passes will put players under pressure, also our defenders.