[Tim Y]

Breedings are MUTUALLY EXCLUSIVE to one another

all from Natalma
1961 NORTHERN DANCER,c,Nearctic 2 18 14 2 2 580,647 81.91
DP = 8-16-15-3-0 DI = 3.00 CD = 0.69
At 2 Won Remsen S (25,000), Coronation Futurity (20,000), Summer S
(10,000), Carleton S (7,500), 2nd Cup And Saucer S (15,000), Vandal S
(7,500)
At 3 Won Preakness S (150,000), Kentucky Derby *Nt (125,000), Flamingo S
(100,000), Florida Derby (100,000), Queen's Plate (50,000), Blue
Grass S (25,000), 3rd Belmont S (125,000)

1963 Arctic Dancer,f,Nearctic 1 2 0 1 0 2,500 3.68
DP = 8-16-15-3-0 DI = 3.00 CD = 0.69
At 2 2nd My Dear S (10,000)

1966 Northern Native,c,Nearctic 2 13 4 1 3 19,150 3.19
DP = 8-16-15-3-0 DI = 3.00 CD = 0.69
At 3 2nd Plate Trial (10,000), 3rd Toronto Cup H (10,000)
1967 Barren
1968 Northern Ace,c,Nearctic 3 22 5 4 3 15,960 1.52
DP = 8-16-15-3-0 DI = 3.00 CD = 0.69

same "theoretical" genes but NOT the same outcome

You can repeat the breedings over and over
=broodmare ROMANELLA (ITY), 1943, =El Greco (Ity)- =Barbara Burrini (Ity) by *Papyrus.

1952 *RIBOT,c,=Tenerani (Ity)
DP = 2-6-2-2-2 DI = 1.80 CD = 0.29
At 2 Won Gran Criterium (ITY), Criterium Nazionale (ITY)
At 3 Won Prix De L'arc De Triomphe (FR), Pr Del Jockey Club (ITY), Pr
Emanuele Filiberto (ITY), Pr Pisa (ITY), Pr Besana (ITY)
At 4 Won Pr Del Piazzale (ITY), Prix De L'arc De Triomphe (FR), King
George 6th & Queen Elizabeth S (ENG), Gp Di Milano (ITY)

1957 =Rosselina (Ity),f,=Tenerani (Ity) Unraced
DP = 2-6-2-2-2 DI = 1.80 CD = 0.29
1958 *Rousseau 2nd,c,=Owen Tudor (Gb) Unraced
DP = 8-8-10-4-2 DI = 1.91 CD = 0.50
1961 =Romagnola (Gb),f,=Tenerani (Ity) Unraced
DP = 2-6-2-2-2 DI = 1.80 CD = 0.29

The randomness of genes at cross over make their expression in the same phenotype a guessing game.

4 or 5 breedings between Fair Play and Mahuba produced two stakes winners:Man O'War and his good sister who won minor stakes.....