Topic: Dosage System | The Racing Forum

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April 3, 2001 at 10:26 #4248
Steve M
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As there appears to be some interest in from the general forum I have included this here. I originally wrote this a couple of years ago. Niniski and Shirley Heights are among those to have been added since. A more readable format (no doubt most of the formatting will be lost) appears on the form-sires website.

The Dosage system

Correct Dosage to cure system’s ills

By Steve Miller

The Dosage system has become more "Euro friendly"

The Dosage "pedigree-by-numbers" system has been around for a long time, yet it is only now that it is beginning to catch on in Europe and in the UK. In America no one in his or her right mind would consider buying an unraced horse without first referring to its Dosage. In the UK it has been viewed with mistrust, as if it were akin to a form of alchemy, which has had the audacity to meddle in areas of conventional pedigree analysis. Most objections to the Dosage system have been levelled at it from a European perspective, however, saying that it is not appropriate for European racing due to certain important stallions being missing from its roster of super sires.

Inclusion of Sadler’s Wells, Ela-Mana-Mou and Busted

Fortunately, due to my own research, at the behest of Dr Steven Roman (the originator of the modern system), Dosage has gained greater credence in Europe through the inclusion of the Irish-based sires Sadler’s Wells and Ela-Mana-Mou in particular (and more recently Busted). These were the most serious omissions from the system from a European point of view. Sadler’s Wells has proved a significant source of Classic middle-distance stamina, while Ela-Mana-Mou bridges a critical gap reaching back to Alycidon and his sire Donatello as an unqualified source of extreme stamina (Professional category). Busted has been accepted as a Solid chef-de-race.

Dosage remains the most important tool for predicting the distance potential of horses based on certain sires in the first four generations of their pedigrees and is especially useful when form information is either scant or absent. The sires must be included among the assigned chiefs of breed (or so-called chefs-de-race).

Categories

Chefs are divided into five categories: Brilliant, Intermediate, Classic, Solid and Professional. The categories correspond to a range of distance potential, from Brilliant (most speed, least stamina) to Professional (least speed, most stamina). Classic represents the ‘ideal’ balance of speed and stamina.

Chefs may be assigned to more than one category, with points split between the categories. A chef in the first generation is assigned 16 points, decreasing to eight, four and two points, to account for the diminishing influence of sires farther back in the pedigree. It assumes that a grandsire is half as influential as a sire, etc.

Three statistics are generated by Dosage: a Dosage Profile (DP), a Dosage Index (DI), and a Centre of Distribution (CD).

Centre of distribution scale

Brilliant Intermediate Classic Solid Professional +2.00 +1.00 0.00 -1.00 -2.00 

As an example, horses with a DI higher than 4.00 or a CD higher than +1.25 are not reckoned to be able to win high-class races at 10 furlongs or more carrying level weights at equal weight-for-age. Although as Kathleen Jones rightly points out in her chapter on the Dosage system in the last edition of Form Sires, "horses don’t race against distances, they race against other horses".

When Generous won the Derby, for example, he beat a field of non-stayers, with Marju and Star Of Gdansk (who both subsequently proved to be milers) filling the places. Star Of Gdansk’s Dosage figures were a clear signal that he stood precious little chance in a Group 1 race at 12 furlongs (DP 10-10-9-1-0 = 30, DI 4.45, CD +0.97). Two-thirds of his points (20) are grouped in his first two categories (Brilliant and Intermediate) and only one point is registered in the stamina wing of his pedigree. The fact that the horse was able to achieve a place in the Derby when it appears evident that he would not stay is a tribute to the quality of the horse. He was always going to be up against it with Generous, however, who looked a blueprint for a Derby winner, with nine of his 22 points in his stamina wing (DP 4-1-8-9-0 = 22, DI 0.69, CD 0.00).

A DI of 1.00 and/or a CD of 0.00 indicate an ideal balance of speed and stamina. The CD is a more precise statistical indicator of distance potential than the DI.

Origins

The technique used for classifying thoroughbred pedigrees by type, originated in the early part of the 20th century from the research of the Frenchman Lt. Col. J. J. Vuillier. In his classic study of the extended pedigrees of the best runners in England and France (Les croisements rationnels dans la race pure) Vuillier observed that very few stallions appeared with any great frequency. He called these stallions chefs-de-race. He also noted that the degree of inheritance attributed to these chefs was essentially constant in all pedigrees, the absolute value (or Dosage figure) varying from sire to sire. He demonstrated that in successive 15 to 20-year time frames, new series of chefs emerged which eventually established their own fixed degree of influence. This process, in which new series of chefs periodically become dominant, provides a rational model for the evolution of the thoroughbred racehorse. Vuillier believed that the objective in breeding should be to attain Dosage figures in the foal as close as possible to the established Dosage figures for the breed. Vuillier practised his theories in the employ of The Aga Khan III, breeder of such notables as Bahram, Majideh, Mahmoud and Nasrullah.

Some years later, the Italian Dr Franco Varola (in Typology of the racehorse and The functional development of the thoroughbred) developed a modified version of Dosage that retained the principle that thoroughbred evolution proceeds through the influence of a much smaller number of the stallions in any era than is widely appreciated. Varola did, however, shift the emphasis from quantity (i.e. the degree of inheritance associated with individual sires) to quality (i.e. the pattern of aptitudinal traits inherited from key ancestors). Discounting the generation in which his expanded list of chefs appeared, he arrived at a distribution of aptitudinal traits in a given pedigree that described the "type" of horse being analysed. The most significant point made by Varola was that the characteristics transmitted by sires were not necessarily those they possessed themselves as racehorses. The focus, instead, was entirely on the qualities passed on as breeding animals. Thus, in contrast to conventional pedigree analysis – which is based on an historical perspective of ancestral performance – Dosage relies on the dynamics of inheritance.

The approach used by Dr Roman, which first appeared publicly as a series of articles in Leon Rasmussen’s Bloodlines column in the Daily Racing Form, prior to the 1981 Kentucky Derby, has been to combine the basic ideas of Vuillier and Varola, incorporating both, "quantitative and qualitative components in the hope of providing additional insights". Dr Roman chose to use four-generation pedigrees instead of the extended pedigrees used previously. He re-introduced Vuillier’s approximation of a genetic effect, by halving the influence of any chef in each successive earlier generation. He also established a statistical method for evaluating the results of his analysis. In this framework, Dosage in its latest manifestation was developed.

Example

As an example, I have applied these rules to the brilliant dual Derby (French and Irish) and Prix de l’ Arc de Triomphe winner Montjeu (by Sadler’s Wells) in the following:

Dosage Profile B I C S P 5 1 22 8 0 = 36 points Dosage Index B I 1/2C 5 + 1 + 11 = 17 __ __ __ __ __ = 0.89 11 + 8 + 0 = 19 1/2C S P Centre of Distribution 2xB I S 2xP TOTAL (10 + 1 = 11) – (8 + 0 = 8) 3

3 divided by 36 = +0.08

Benchmark norms for the English Thoroughbred are:

DI = 2.40

CD = +0.70

Montjeu’s DI and CD are both much lower than average (DI = 0.89, CD = +0.08), which means that he has more stamina than the typical thoroughbred, while his Centre of Distribution being close to zero also suggests that stamina and speed are almost perfectly balanced.

With the influence of Sadler’s Wells stripped out, Montjeu would not have been an obvious candidate to land the spoils in Europe’s major middle-distance Group 1 races. He would have scored no points in the stamina wing of his profile in either his Solid or Professional categories.

With the Sadler’s Well Classic/Solid influence factored in, however, Montjeu is a near blue print of past Irish and French Derby winners. He scores 8 points in his Solid category and 8 points are added to his middle Classic category. This pushes his Dosage Index to below 1.00 and puts him on a Centre of Distribution of close to zero.

Montjeu’s pedigree Points = 16 8 4 2 Nearco B/C Nearctic Lady Angela Northern Dancer B/C Native Dancer I/C Natalma Almahmoud Sadler’s Wells C/S Hail To Reason C Bold Reason Lalun Fairy Bridge Forli C Special Thong MONTJEU Derring-Do High Top C Canenae Top Ville Charlottesville Sega Ville La Sega Floripedes Val de Loir Tennyson Tidra Toute Cy Zeddaan Adele Toumignon Alvorada 

Note: Assigned Chefs-de-Race sires appear in bold italics.

B = Brilliant, I = Intermediate, C = Classic, S = Solid, P = Professional.

Past winners of the Irish Derby

1998 Dream Well DP 8-3-22-10-1 = 44 DI 1.00 CD +0.16 1997 Desert King DP 4-4-25-0-1 =34 DI 1.52 CD +0.29 1996 Zagreb DP 2-0-15-3-0 =20 DI 0.90 CD +0.05 1995 Winged Love DP -0-11-7-0 = 20 DI 0.60 CD -0.15 1994 Balanchine DP 7-2-14-1-0 = 24 DI 2.00 CD +0.62 1993 Commander In Chief DP 9-4-27-0-0 = 40 DI 1.96 CD +0.55 1992 St Jovite DP 4-0-16-4-2 = 26 DI 0.86 CD 0.00 1991 Generous DP 4-1-8-9-0 = 22 DI 0.69 CD 0.00 1990 Salsabil DP 7-2-18-13-2 = 42 DI 0.75 CD -0.02 1989 Old Vic DP 9-1-18-8-2 = 38 DI 1.00 CD +0.18

Average for past ten renewals:

DP 5.6-1.7-17.4-5.5-0.8 = 31, DI 1.13, CD +0.17

From the preceding table we can see that the highest Dosage Index (most speed potential) was set by one of the two fillies to have won the Irish Derby in the past ten renewals, Balanchine on 2.0. The lowest DI (most stamina potential) was set by Winged Love on 0.60. This establishes a fairly narrow range, allowing us to discard anything outside of these parameters in relation to the 1999 renewal.

Two zero CDs (representing the ideal balance between speed and stamina) were recorded by St Jovite and Generous, but Zagreb and Salsabil can also be included with these, as their CDs are just either side of zero. Seven of the ten have DIs of 1.0 or below.

As might be expected, all horses scored in the stamina wing of their Dosage profiles except Commander In Chief, although he scores highest of the other winners (27 points) in his middle Classic category, so that his overall Dosage index is still below 2.0.

A selection of ante-post leaders for last year’s Irish Derby

Montjeu DP 5-1-22-8-0 = 36 DI 0.89 CD +0.08 Daliapour DP 6-2-20-10-0 = 38 DI 0.90 CD +0.11 Tchaikovsky DP 5-2-19-8-0 = 34 DI 0.94 CD +0.12 Mutafawaq DP 3-3-17-5-0 = 28 DI 1.07 CD +0.14 Port Bayou DP 4-5-12-0-1 = 22 DI 2.14 CD +0.50 Beat All DP 7-6-18-0-1 = 32 DI 2.20 CD +0.56

The selection above is arranged from lowest DI (Montjeu – most stamina potential) to highest DI (Beat All – least stamina potential) in descending order. Montjeu has a textbook Dosage profile for a Group 1 performer at middle distances. He has a high concentration in his middle Classic category (22 points) and a CD of close to zero (+0.08), as well as having the most stamina potential of the selection, along with Daliapour.

Mutafaweq and Tchaikovsky are the closest matches to the average figures. Port Bayou and Beat All are slanted toward speed, but significantly all three also score in their Professional categories (extreme stamina influence). Beat All and Port Bayou both have DIs greater than 2.0 and while they could not be ruled out, Sir Harry Lewis was the last to win this (in 1987) with a DI of greater than 2.0 (2.52).

In the Irish Derby we were looking for a horse with a DI of around 1.0 (or lower) and a CD of as close to zero as possible, that also scored in the stamina wing (Solid and/or Professional categories) of its profile. All of these score in the stamina wing, but no horse scores in both categories.

We can say, however, that Montjeu appears better suited than either Port Bayou or Beat All (the ante post favourite for the race) and had most to fear from Daliapour, Tchaikovsky and Mutafaweq from an aptitudinal point of view (considerations of ability aside). Given ground with some cut, Montjeu and Daliapour looked like taking the beating. Faster conditions would have counted against these two, however, as both their superior stamina potential and going preference would have been negated to an extent. The figures also told us that the ante post favourite Beat All was in fact the least suited to the race of the above selection compared to past winners of the race. This was of course a very valuable piece of information (Beat All in fact finished fourth).

The fact that the preceding table threw up the first three home in the Irish race is as much to do with the fact that all three were sired by Sadler’s Wells – who is a proven prepotent source of middle-distance stamina – as with anything else. However, the system also identified the first three home in the 1998 St Leger (a race in which the Dosage system proves particularly successful), for example. Nedawi, who won the race, scores 8 points in the stamina wing of his profile, 2 points in his Solid category and 6 points in his Professional category.

The influence of Ela-Mana-Mou

Turning to another example, before Ela-Mana-Mou’s inclusion into the Dosage system the Dosage numbers of his seven Group 1 winners looked in desperate need of revision. They previously appeared as:

Sumayr 1-2-7-0-0 = 10 DI 1.86 CD +0.40 Almaarad 3-2-1-0-6 = 12 DI 0.85 CD -0.33 Eurobird 2-3-5-8-0 = 18 DI 0.71 CD -0.06 Natski 1-3-8-8-0 = 20 DI 0.67 CD -0.15 Emmson 6-8-4-0-0 = 18 DI 8.00 CD +1.11 Snurge 5-2-7-0-0 = 14 DI 3.00 CD +0.86 Double Trigger 1-2-1-0-0 = 4 DI 7.00 CD +1.00

Of these only Almaarad, Eurobird and Natski look anything like they should, deriving points in the stamina wing of their Dosage profiles from other sources, such as Crepello and Donatello II (Almaarad) and from Sea-Bird (Eurobird and Natski). The revised ratings, factoring in a Professional influence from Ela-Mana-Mou read:

Sumayr 1-2-7-0-16 = 26 DI 0.33 CD -1.07 Almaarad 3-2-1-0-22 = 28 DI 0.24 CD -1.28 Eurobird 2-3-5-8-16 = 34 DI 0.28 CD -0.97 Natski 1-3-8-8-16 = 36 DI 0.28 CD -0.97 Emmson 6-8-4-0-16 = 34 DI 0.89 CD -0.35 Snurge 5-2-7-0-16 = 30 DI 0.54 CD -0.66 Double Trigger 1-2-1-0-16 = 20 DI 0.21 CD -1.40

Note that Double Trigger has moved from having the second highest DI of 7.00 (behind Emmson on a DI of 8.00), which is clearly completely inaccurate, to the lowest of 0.21 (below that of Almaarad on a DI of 0.24), while his CD has moved from +1.00 to -1.40. The others in this sample also look much better placed on DIs of well below 1.00 and negative CDs, as they are proven at or beyond middle-distances, or at extreme distances. This highlights a critical observation in Dosage analysis, that while a high overall score for the Dosage profile is no necessary indication of ability, the higher the score the more accurate the reading of stamina potential is likely to be. Double Trigger’s previous profile relied on a score of just 4 points. His revised profile is based on 20 points, making it a much more reliable one.

The revision moved Double Trigger to his rightful place alongside the likes of Sagaro, Le Moss (and Le Moss’s full brother Levmoss ten years before him), DI 0.71 CD -0.08, and Ardross, DI 0.29 CD -1.11, as befits the winner of multiple Group races at 2 miles plus. Sagaro, Le Moss and Ardross represent a golden period of quality staying horses in Britain, winning seven Gold Cups between them during the period 1975-82. Such quality had not been witnessed since the late 1940s (when the virtually unbeatable stayer Alycidon – Ela-Mana-Mou’s great, great grandsire – reigned supreme).

Ela-Mana-Mou is an unqualified influence for stamina, transmitting characteristics passed down from the likes of Alycidon, Donatello II, Chateau Bouscaut, Son-In-Law, Mieuxce, Bayardo, Hurry On and Massine (all Professional chefs-de-race sires themselves) from his fourth, fifth and sixth generations (which as far as his progeny are concerned fall outside the scope of the Dosage system), rather than the sharper influences of the likes of Hyperion and Petition in his third generation (who are included in the Dosage calculations of his progeny).

Ela-Mana-Mou is clearly capable of siring horses that stay considerably further than he was capable of on the racecourse (or than the influence of his more immediate predecessors suggests). He provides the missing link from the great out-and-out (Professional) stayers of the past to current and subsequent generations of bloodlines stemming from Alycidon and his sire Donatello II (1934).

To quote Dr Roman’s guiding motivation "greater accuracy and increased predictability depends in large part on a continual modification and refinement of the chef-de-race list, guided by the principle of a better description of reality".

As I have put forward in this paper, the inclusion of certain influential European-based sires greatly assists with this "better description".

STEVE MILLER
April 3, 2001 at 19:23 #101641
ALI
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- Total Posts 43
Exellent reading Steve, appreciated. I’ve printed that off to to go alongside my step by step guide to calculating dosage figures. I find that very useful.

Have you paid any interest to the tattersalls breeze-up sales Steve on the 18th and 19th of this month. Just out of interest.
April 4, 2001 at 10:35 #101642
Steve M
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No, I’m fully invested in thoroughbreds at the moment Ali. A more readable version of the above appears on the formsires.co.uk website under ‘What is Dosage?’
January 21, 2002 at 21:37 #101643
Daylight
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#Moderation Mode

<a href=”https://theracingforum.co.uk/cgi-bin/ikonboard/topic.cgi?forum=23&topic=7″ target=”_self”>Moved here</a>
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