寫法改變 但意義一樣 結果卻不同

A:

input: lowprice(30,"現股價小於"), capital(10,"股本小於"); 

condition3 = C < lowprice and getfield("股本(億)", "D") <= capital; 

condition4 = average(C, 100) > average(C, 300); 

 if condition3 and condition4 then 

ret = 1; 

===================

B:

input: lowprice(30,"現股價小於"), capital(10,"股本小於"); 

 value2=Getfield("收盤價", "D");

condition3 = value2 < lowprice and getfield("股本(億)", "D") <= capital; 

condition4 = average(value2, 100) > average(value2, 300); 

 if  condition3 and condition4 then 

ret = 1; 

請問這樣跑出來的回測結果為何會不同??

謝謝