Looking at Mr. Prospector in the American Classics

         Ed DeRosa’s recent blog post about Mr. Prospector’s dominance in the Belmont Stakes in recent history made me wonder if the success of his progeny in the Belmont was significant or just the result of the popularity of his male offspring at stud.  After all, every year the University of Kentucky has won a NCAA basketball championship, the Yankees have won the World Series.  We will see how 2012 turns out for the Yankees.  There is no direct connection here – just that both teams have been good over a long period of time.  I wondered if something similar was true for descendants of Mr. Prospector (“Mr. P.”) in the Belmont. 

           

            First things first, go read Ed’s post if you haven’t already – it’s great.  I will wait.  To me, the post has two very interesting points:  the success of Mr. P in the Belmont has come from a variety of different sons and grandsons and that the success of Mr. P in the Belmont may be somewhat of an illusion.  Let me explain. 

           

            First, as Ed notes “descendants of Mr. Prospector have won 13 of the past 17 Belmont Stakes, including 11 of the past 14, seven of the last nine, and each of the past three.”  But, this success has been through the offspring of seven different sons – “Afleet, Fappiano, Forty Niner, Fusaichi Pegasus, Gone West, Gulch, Kingmambo, and Seeking the Gold.”  I wondered if this level of success was any different than Mr. P in the other two Triple Crown races.    

                       

	Kentucky Derby Winners (2012 to 1995)
Year	Horse	Sire Line
2012	I'll Have Another	Mr. P
2011	Animal Kingdom	Blushing Groom
2010	Super Saver	Wavering Monarch
2009	Mine That Bird	Mr. P
2008	Big Brown	N. Dancer
2007	Street Sense	Mr. P
2006	Barbaro	Roberto
2005	Giacomo	Holly Bull
2004	Smarty Jones	Mr. P
2003	Funny Cide	Mr. P
2002	War Emblem	Mr. P
2001	Monarchos	Wavering Monarch
2000	Fu. Pegasus	Mr. P
1999	Charismatic	N. Dancer
1998	Real Quiet	Mr. P
1997	Silver Charm	Buckpasser
1996	Grindstone	Mr. P
1995	Thunder Gulch	Mr. P

           

            As for the first point, descendants of Mr. P have won 10 of the past 18 Kentucky Derbies, including 6 of the past 14, 4 of the last 9, and 1 of the past 3.  Thus, over the past 18 years, male descendants of Mr. P have won the Kentucky Derby approximately 56 percent of the time while they have won the Belmont approximately 76 percent of the time.  This twenty percent difference in win rate appears significant but given the 20 horse field of the Derby and the relative small sample this difference may not persist. 

           

	Preakness Stakes Winners (2012 to 1995)
Year	Winner	Sire Line
2012	I'll Have Another	Mr. P
2011	Shackleford	N. Dancer
2010	Lookin' at Lucky	Mr. P
2009	Rachel Alexandra	N. Dancer
2008	Big Brown	N. Dancer
2007	Curlin	Mr. P
2006	Bernardini	S. Slew
2005	Afleet Alex	Mr. P
2004	Smarty Jones	Mr. P
2003	Funny Cide	Mr. P
2002	War Emblem	Mr. P
2001	Point Given	Mr. P
2000	Red Bullet	Mr. P
1999	Charismatic	N. Dancer
1998	Real Quiet	Mr. P
1997	Silver Charm	Buckpasser
1996	Louis Quatorze	N. Dancer
1995	Timber Country	Mr. P

            In the Preakness, male descendants of Mr. P have won 11 of the past 18 Preakness Stakes, including 10 of the last 14, 6 of the last 9, and 2 of the past 3.  Amazingly, a male descendant of Mr. P won the Preakness from 2000 to 2005.   Boosted by this six year stretch, male descendants of Mr. P have won the Preakness approximately 61 percent of the time.   While this figure is higher than the Derby, it still does not approach the 76% win rate of the Belmont.   The higher success rate of Mr. P male descendants in the Belmont is probably best explained in Ed’s piece in a quote from Anne Peters

The Gulch and Fappiano branches are your main ones and show how the Mr. Prospector line is diverging away from the speed that it was known for. He was so brilliant, that breeders tend to keep piling on the stamina with him, and it’s worked.

            I found this quote really interesting because it suggests that the success of Mr. P line stallions in the Belmont is not necessarily attributable to Mr. P himself, but to the stamina heavy mares that were bred to him to temper his natural speed.  Given the domestic bias towards speed, the only way these stamina genes survived in our horses was to be bred to a sprinter like Mr. P.  A review of the pedigrees of the 15 Belmont winners descended from Mr. P supports this conclusion as only one (Ruler on Ice) is inbred to Mr. P.  Oddly enough, Ruler on Ice is only inbred to Mr. P because his sire Roman Ruler was inbred to Mr. P.  While Drosselmeyer and Summer Bird were sons of Mr. P line stallions, they each carried three different lines of Northern Dancer in their pedigrees making Northern Dancer much more influential to their genetic makeup than Mr. P who only appeared once.  As in all things, it is not just as simple as picking out the horses who are male descendants of Mr. P in classic races like the Belmont.  After all from 2011 to 2008, there were 44 starters in the Belmont, 15 of those were male descendants of Mr. P, and their average result was 5.6.  Thus, the stamina influences of the mares in those pedigrees must be given equal weight. 

Postscript

            Of course, Union Rags, the winner of the 2012 Belmont, promptly undercut this post on Saturday afternoon as he is a Northern Dancer line stallion, but one who is inbred to Mr. P (3 by 4).  He is also inbred to Northern Dancer and has significant stamina influences throughout his female family. Atigun finished third, which was the best finish for a male descendant of Mr. P in the 2012 Belmont