Uneven Cooking There are very simple things to remedy the problem of uneven cooking. One is the most common is fixing an uneven oven. If your oven has a slight lean to the left or right, or tilt forward or back, you will see the effect on the cooking inside the oven. Why? Because heat rises and as water flows toward gravity through the path of least resistance, so does air that is not forced by something else. This is the most common reason for uneven cooking. Second would be the weakening of door hinges. As this could be prevented by a stronger spring or better pulley is irrelevant because it has been built when I see it. The spring on the hinge cannot sustain the weight of the door and the door opens ever so slightly and reduces efficiency of the oven from letting heat out of the front instead of vented areas. Now there are other reasons that usually also effect temperatures as well like one of your electric elements is not working because of the use of bake and broil to get oven to temp or your convection fan is not turning at all or turning at a lower rpm than factory specification, usually a separation of a winding in a motor, which will eventually go out completely. Depending on temperature and usage. There is one more thing that is less common, yet happens on new and older ovens for different reasons and this is only one half of the flame tube in a gas oven lights up and the other half either takes more time… smelling gas usually goes hand and hand with this, or blocked outlets, which can be on a new oven because there are shavings of metal blocking them and you would get discolored longer flames on the ones not blocked; or clogged with sediment from the burning of natural gas. This is not based on any particular age of oven, but how much oven is used and how clean the gas burns, which could also be changed by altitude from atmospheric pressure. But those last bits were just physics and not keeping it simple. I always say knowledge is power and who am I to not share it?