The Confusion of Quantity With Quality

I am going to resort to Racehorse Breeding Theories, Chapter 14, pages 273-276, to continue this discussion of the Bruce Lowe Figure System.

“Lowe traced the winners of the English Oaks, Derby, and St. Leger through their female families back to the first registered mare found in the English Stud Book. . . .

“Lowe found that some families had produced many more classic winners than others. The family that had produced the most classic winners at that time . . . he labeled the Number 1 Family; the family with the second-highest total was the Number 2 Family and so forth. . . .

“Estes’s work with statistics showed that the Figure System was actually a classic case of opportunity. The most populous female families were, in general, the most successful. The families with the larger number of classic winners were the same families who accounted for the larger proportion of the breed. And their success was in proportion to their representation. A family might account for 12 percent of the breed through the tail-female line, and its members would have won 12 percent of the classics, more or less. . . .

“Furthermore, the Lowe families from first to least, for instance, also follow their rankings in having the largest number of claiming race winners. The rankings, in the final estimation, are a measure of quantity but not quality.”

I would like to emphasize that point about the families with the most classic winners also having the highest number of foals. If we substitute stakes winners for classic winners and examine sales foals of 2003-2007, the same holds true today. The chart below illustrates.

Family Number          Foals          Stakes Winners

1                                    10,036                342

4                                     7,893                 255

9                                     6,640                 245

2                                     5,837                 188

The four most popular families (by number of foals) today are one (10,036), four (7,893), nine (6,640), and two (5,837). No other family has more than 5,000 foals.

Not coincidentally, those same four families also rank first through fourth, in the same order, by number of stakes winners: one (342 stakes winners), four (255), nine (245), and two (188).

The above also illustrates that popularity waxes and wanes over time. Among the top ten Lowe families, numbers six (only 1,201 foals), seven (1,503 foals), and ten (1,747 foals) have declined in popularity over time.

The chart below summarizes racing results for all 21 groups. APPPSW stands for average Performance Points per stakes winner, a measure of the quality of stakes winners involved, with 620 being average.

Family Number      Foals         Stakes Winners      %       APPPSW          PPI (Result)      Rank

19                               1,475                   47                 3.19         823                     1.24                 1

3                                 4,361                 147                 3.37        764                      1.22                 2

9                                 6,640                245                 3.69        694                      1.21                 3

22                               1,677                  57                  3.40        734                      1.18                 4

13                               2.258                  86                  3.81        650                      1.17                 5

11                                1,171                  48                  4.10       606                       1.17                 6

10                               1,747                   74                 4.24        544                      1.09                 7

1                               10,036                342                3.41         669                      1.08                 8

21                               1,292                  46                 3.56         643                      1.08                9

14                               2,523                  92                 3.65        622                       1.07               10

4                                 7,893                 255                3.23        608                      0.93               11

5                                 3,378                 101                2.99        651                       0.92               12

16                               3,430                 121                3.53        541                       0.90               13

all others                   4,584                 158                3.45        529                       0.86               14

8                                 4,637                 151                3.26         561                      0.86                15

23                              2,019                  70                  3.47        523                      0.86                16

2                                5,837                  188                3.22        558                      0.85                17

6                                1,201                    36                3.00        578                      0.82                18

20                              1,371                    41                 2.99        578                      0.82                19

7                                 1,503                   54                3.59        469                      0.80                20

12                               1,681                   56                3.33         486                      0.76                21

The groups are also ranked by their PPIs (results). Ten of the 21 groups have PPIs above 1.00. 11 have PPis below 1.00. That is about as expected. Only three of the ten groups with PPIs above 1.00 were from the top ten Lowe families: family number three finished second, number nine finished third, and number one finished eighth. The top ten Lowe families should have had at least five groups in the top ten by PPI (results); they actually had only three.

The chart below compares prices with results. For example, family number 19 had a Price Index of 0.98 and a PPI (result) of 1.24. The latter is 0.26 higher than the former. That is an excellent (positive) result. Positive numbers in the Comparison column are good. Negative numbers are bad.

Family Number      Foals         Price Index          PPI (Result)         Comparison

19                               1,475             0.98                       1.24                      +0.26

3                                 4,361            1.01                        1.22                       +0.21

9                                 6,640           0.99                        1.21                       +0.22

22                               1,677            1.01                        1.18                        +0.17

13                               2.258           1.08                        1.17                        +0.09

11                                1,171            1.05                        1.17                        +0.12

10                               1,747            0.95                        1.09                       +0.14

1                               10,036           0.99                        1.08                       +0.09

21                               1,292            1.05                        1.08                       +0.03

14                               2,523            1.00                        1.07                       +0.07

4                                 7,893            0.99                        0.93                     –0.06

5                                 3,378            1.04                        0.92                     –0.12

16                               3,430           0.98                        0.90                     –0.08

all others                   4,584          1.02                          0.86                     –0.16

8                                 4,637           1.02                         0.86                     –0.16

23                              2,019           1.04                          0.86                    –0.18

2                                5,837           0.98                          0.85                    –0.13

6                                1,201           0.87                          0.82                    –0.05

20                              1,371          0.89                           0.82                    –0.07

7                                 1,503          1.01                          0.80                     –0.21

12                               1,681          1.04                          0.76                     –0.28

Interestingly, all ten groups with PPIs above 1.00 also had positive Comparison numbers. All 11 groups with PPIs below 1.00 also had negative Comparison numbers.

You probably want to take those results for family number 19 with a grain of salt. Curlin (13,802) accounted for more than a third of the total Performance Points garnered by that family (38,696). Without Curlin the PPI of this group falls from 1.24 to 0.80.

Family number 12 was the worst in the chart above with a Price Index of 1.04, a PPI of 0.76, and a Comparison number of –0.28. I can not come up with a good explanation for this poor result.

But do not take these numbers too seriously. Do not take this theory seriously at all. As I said at the beginning of my last post, the Bruce Lowe Figure System has long been discredited. And for very good reasons.

I will conclude with another quote from Racehorse Breeding Theories (page 276):

“Lowe’s work was interesting because it urged breeders to take more thought about the bottom lines in their breeding plans, but the theory was not thought out with an understanding of statistics and opportunity. As a result, it would have little use for the practical breeder today.”

Many breeding theories are “not thought out with an understanding of statistics and opportunity.” Many breeding theories confuse quantity with quality. The Bruce Lowe Figure System was a classic example of this confusion.

I hope these posts have helped readers to a better understanding of the statistics of pedigrees. Specifically, NOT to confuse quantity with quality.

 

 

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