All Time leading Sires by AEI

[Scott]

Interesting history note of former producers - All time leading sires by AEI

[Sires......... ..........Foals .....SWS........AEI
1. Bold Ruler.......... .356......82 /23%......7.73
2. Alydar ............... 689......77 / 11%.....5.21
3. Nasrullah............ 425......98 / 23%.....5.16
4. Northern Dancer..635.....146 / 23%......5.14
5. Nijinsky...............850.....155 / 18%.....4.74
6. Danzig................886......165 / 19%.....4.53
7. Tom Fool.............276.......36 / 13%.....4.51
8. Hail To Reason.....308.......43 / 14%.....4.47
9. Fappiano.............410........48 / 12%.....4.46
10. Bull Lea.............377........58 / 15%.....4.37
11. Mr Prospector....1157.....176 / 15%.....4.25
12. Seattle Slew.......933......100 / 11%.....4.12

[louis finochio]

I did the same search and here's some more of value lifetime AEI:

Mill Reef 4.36
Sadlers Wells 4.15
Nureyev 4.10
Storm Cat 4.11
Ribot 4.09
Round Table 4.01
Hoist the Flag 3.89

With the elevated purses today the old time stallions would have a higher lifetime AEI than in their day.

[brogers]

With the elevated purses today the old time stallions would have a higher lifetime AEI than in their day.

That doesn't make sense. The AEI is created by looking at the average earnings and equating it to a base for the racing year so even if the purses rise, it is still calculated against the same average (1.00).

[louis finochio]

If the elevated purses of today dont make a stallions AEI higher because of the average, explain how it wouldnt affect the same. Thanks.

[brogers]

The AEI was developed by the late Joseph Estes during his time as editor of The Blood Horse. The average earnings of all runners is represented by an index of 1.00, and is calculated for each calendar racing year. A stallion's AEI is calculated for each year he has runners and then averaged for all years his progeny have raced.

Thus, it makes no difference if the prizemoney rises as it is an AVERAGE for the calendar year. You are comparing apples to apples in this case.

If the average purse in Bold Ruler's time was $1,000 (1.00) and Bold Ruler's progeny averaged $7,700 then he would have an AEI of 7.70. If the average purse for horses that race during Storm Cat's reign was $15,000 (1.00) and the progeny of Storm Cat averaged $60,000 then he would have an AEI of 4.00. Money can come and go but the AEI calculates the average prizemoney as an index so it remains constant.

There are a couple of flaws with the AEI. The obvious flaw with the AEI is that it fails to take into account the number of starts made by each individual. Durable horses are more likely to push their AEI up simply by making more starts. Fragile horses are at a disadvantage in that their lower AEI is merely a function of fewer earnings opportunities. Also, horses that win races with extraordinary prizemoney (like say a Sunshine Millions race) earn themselves a massive AEI and can distort the stallions AEI, especially if he has small numbers of foals.

[louis finochio]

Stallions that produce only one big horse will have an inflated AEI. A breeder must do his homework and discover why a one horse stallion AEI is so high. Thanks Yours in Sport Louis.

[Mahubah]

The reason the great old time stallions would have a higher AEI under the modern purse structure is that the difference between purses available to the top horses and purses available to ordinary runners is much larger today than it was prior to World War II. For example, Man o' War got only $7950 for winning the Belmont Stakes, where a cheap claimer might have taken down a $100 purse; that's a difference of $7850. Today, the same class of cheap claimer might get, say, $3500, for a win, but the winner of the 2005 Belmont Stakes took down $600,000, a difference of $596,500.

As Estes himself said in 1948, "While the Average-Earnings Index is useful in comparing contemporary stallions, it does not satisfactorily bridge the gap of two racing eras. Around the time of the First World War, important stakes were run for relatively small purses. The ratio of stakes purses to overnight purses was much smaller than it became around the time of the Second World War. A good stakes horse in the earlier period earned only slightly more than a good allowance horse whereas a good horse in the late 1930s and 1940s could earn many times more than an allowance horse. While the overall increase in purses is compensated for by the use of the index of 1.00 for each year, the variance in purse structure -- whereby the ratio of earnings of exceptional horses to lesser-class horses increased in later years -- is reflected in a generally higher Average Earnings Index for prominent stallions in recent times than was possible for prominent stallions in the earlier period."

[Scott]

It wasn't until the late 70's and early 80's that computer processing led to another statistical analysis - Comparable Index -, which allowed a comparison of a particular mare's foals from one sire to another. This was more informative of a sire's production record.

In 1997 the Jockey Club's database was further refined by using a Structered Query Language (SQL) database, allowing further statistical analysis. This database gave separation of a sire's indexes by each crop year, instead of the index representing a cumulation for all of a sire's progeny record.

Now CI reports can be generated from foals in utero, weanlings or yearlings that breeders can get a feel for how "well bred " (by previous track earnings record) these foals are. This database improvement also allowed the computation of AEI for current year runners, 2 yr olds, male and female runners, dirt or turf runners.

But using AEI based on average earnings can be inflated with six and seven figure earners. This could be better represented by using a median earnings index that limits these high earners influence on these statistics.

For even greater relevance, Blood Horse' s Marketwatch came up with an analysis that calculated AEI for every runner of a sire, looking at AEI as a pecentage basis from what these foals accomplished as individuals.

From this study performed by Marketwatch by using Storm Cat foals from 1992 to 1998, you can see how difficult it is for even the best stallions to get runners that perform better than the average of 1.00.

Results of Storm Cat's 1992 - 1998 foals - (446 foals - 97 or 21% unraced)

AEI less than 1.00 = 31%
AEI from 1.00 to 1.99 = 18%
AEI from 2.00 to 3.99 = 17%
AEI from 4.00 or higher = 13%

The subject of statistics can be divided into descriptive
statistics - describing data, and analytical statistics -
drawing conclusions from data.

For breeding purposes, I like to look at statistics as a guidance tool, and not neccessarily a map.