How do you decide to make him a steer or leave him a bull?

Actually, I am the derailer. Sorry about that.
There is a very valid school of thought that curve bending performance can be a sort of one shot deal based on within breed heterosis and it is repeatable performance that we look for from a bull.  Larry Leonhardt stressed that continuously.  He also stressed that the object is to breed the kind of bulls that will make the kind of cows that will make more bulls like them.
So, personally, and very inexperiencedly, I believe that if the cow has some flaws that I don't want to see again, I would not save the bull calf no matter how magnificent he looks or how impressive the sire.
But I guess that idea breaks down with terminal cross bulls.

When I was about 7 years old, I was driving around with my Father and my Great Grandfather.  We were looking at cow calf pairs on pasture.

My Great Grandfather said something that I have never and will never forget.

He said "A good bull is 50% of the calf...a bad bull is 90% of the calf". 

Here's a case in point of how culling is hard to do.  I really like this bull calf, but I do not like the udder on his mother.

I am not sure I agree completely.  A breeder must remember that a bull only contributes DNA to their offspring.  All other cell components are derived from the dam.  On a population basis (whole herd), bulls contribute more, but on an individual basis (single animal) cows contribute more. Regardless, if the bull is not out of the (your) absolute best cow (your definition) , he should be steered. There are too many AI bulls and too many average donors.  Female performance and progeny should drive our decision.  Always, always use tried and true (proven, not necessarily promoted) individuals. 

Tallcool1 said:

When I was about 7 years old, I was driving around with my Father and my Great Grandfather.  We were looking at cow calf pairs on pasture.

My Great Grandfather said something that I have never and will never forget.

He said "A good bull is 50% of the calf...a bad bull is 90% of the calf".

Click to expand...

RR#2 Cattle Co said:

I am not sure I agree completely.  A breeder must remember that a bull only contributes DNA to their offspring.  All other cell components are derived from the dam.  On a population basis (whole herd), bulls contribute more, but on an individual basis (single animal) cows contribute more. Regardless, if the bull is not out of the (your) absolute best cow (your definition) , he should be steered. There are too many AI bulls and too many average donors.  Female performance and progeny should drive our decision.  Always, always use tried and true (proven, not necessarily promoted) individuals. 

Tallcool1 said:

When I was about 7 years old, I was driving around with my Father and my Great Grandfather.  We were looking at cow calf pairs on pasture.

My Great Grandfather said something that I have never and will never forget.

He said "A good bull is 50% of the calf...a bad bull is 90% of the calf".

Click to expand...

Click to expand...

I guess I don't understand why you don't agree completely.  Your comments support the quote.  He made this quote 40 years ago.