I did not get to see the game, looking for some real information on his performance.
The Raiders gave up 42 points and that is valid information. You've made person nitpicks with my posts so let me return the favor you seem to discount and deconstruct things you don't want to hear so what information do you consider real information because if you are trying to project his production then start with the 42 and how that happened because you can bet that other teams will not want to give up 42 points and take their chances that they'll get 4 turnovers since the Raiders only forced one, the others were from a WR slip and batted ball, a bad center exchange when Mayfield was trying to audible and the center didn't realize he wasn't behind him, and a deep shot with 15 seconds left in regulation time. Three of those turnovers were gifts and which will get cleaned up.
What Mayfield did is attack the middle of the field with high velocity/low trajectory throws that hit tight windows but the high velocity probably lead to many drops as noted by people who saw the game. Since Baker hadn't taken any 1st team reps his receivers are trying to get used to his throws and the way the ball comes off his hand/spin rate etc. The timing isn't quite there because his ball gets their faster and with more heat. The timing will improve.
Even though they said he knew all of the playbook and they'd use it, they didn't. They used and re-used a limited variety of plays and some of them didn't work so expect them to do more installs for Baker and to see what works and doesn't and that the play calling 'should' get tighter but I will tip my hat to Haley because he put up more points than anyone expected.
Haley's play calling was very aggressive and Mayfield seemed to have some audible wiggle-room and he was also very aggressive when it appeared he made an audible. I did not agree with some of the play calling and throw choices since it seemed Mayfield took deep low-percentage shots when the Browns were up by two TDs late in the 3rd when game management dictated clock control with runs and/or shorter high-percent throw choices. Bottom line, Baker will get fed more of the playbook and it will get tailored to his strengths/minimize his weakness'.
Many things lead to the high score, the turnovers to let the Raiders back in the game which forced the Browns to put the peddle down, the quick scores by Mayfield and Chubb turned the ball back over to the Raider offense which gassed the Browns pass rush and a key injury to the Browns defensive backfield gave Carr an open gate to one side of the field. Pretty much a perfect storm for a high score provided the QB can make plays and Baker made plays.
Much tougher test this week against the Ravens who shut down Pittsburgh in Pittsburgh. I never expected the scoring fest of the first start but I doubt we'll see a repeat this week.