Thanks for all the replies. After reading everyone's posts, I did some research and analysed about 60 paper and film developer's formulas. I have a list of 19 chemicals which made about 60 formulas.
The 19 chemicals are: metol,hydroquinone,phenedone,glycin,Amidol,Ascorbic Acid,Sodium Sulfite,Sodium Carbonate,Potassium Bromide(KBr),Potassium Carbonate,Borax,benzotriazole,Sodium Metaborate,Sodium Bisulfite,Dimezone S,triethanolamine,Citric Acid,Potassium thiocyanate,salicylic acid.
60 formulas are for Kodak D-72,E-72,D-74,Kodak D-51,Kodak D-52 (Selectol),Kodak Selectol Soft,D154,Kodak D-155,D-163,D-166,Ansco 110,Ansco 113,Ansco 120,Ansco 130,Ansco 135,Dupont 51D,Dupond 54D,Defender 55D,Dupond 56D,Ilford ID-20,Ilford ID-22,Ilford ID-30,Gevaert G-251,Gevaert G-261,Gevaert G-262,Agfa 100,Agfa 105,Agfa 108,Agfa 120,Agfa 123,ID24,ID25,ID62,ID78,Gaf 125,GAF 135,Burki and Jenny Cold-Tone,DS-14,
DS-15,Dassonville D-1,Dassonville D-2 (Dupond 61-D),Balagnys Amidol,Belows Amidol,Feins Amidol,Lootens Amidol,Michael A. Smiths Amidol,Westons Amidol,Microdol-X (substitute),Diafine (A),Diafine (B),Accufine,Beutler's Formula (A),Beutler's Formula (B),
Kodalith D-85,Kodak D-11,Kodak D-19,Kodak DK-50,Kodak DK-60a.
Most of above formulas are paper developers, some are film developers. Some developer's formulas were never been published but from someone's analysis.
After reading above formulas I have one impression - if I am using simple table/tea spoon nethod to make developers I might by accident hit the ratio of one of the formulas

.