if A1 == "stephen curry" or "Stephen Curry":
will always be true because it is not doing what you think it is doing. Due to the operator precedence rules your expression is being interpreted like this:
if (A1 == "stephen curry") or ("Stephen Curry"):
According to the Python docs a non-blank string evaluates to True when used in a condition so what this becomes is:
if (A1 == "stephen curry") or true:
which always resolves to true because anything or true = true. The way to fix this should be obvious but there are two other things to consider. First, look in to how you might use the in
operator. Second, if you also want it to work for all case variations (e.g. "Stephen cURRy", "STEPHEN curry", etc.) look in to using the string "upper" method.