Effect of Weight on Horse Performance

[thoroughbred]

As is typical in most topics relating to horse racing, the question of the effect of the weight carried by a horse usually generates controversy.

On the one hand, some say, how could a few pounds, more or less, of a jockey's weight, compared with the much larger weight of the horse itself, make any difference.

On the other hand, it is well known that trainers often seek apprentice jockeys, to gain the advantage of the weigh allowance available with an apprentice.

When I did the research that led to my paper, "Engineering Analysis of Thoroughbred Racing", (which by the way can be seen in its entirety at Documentation link at the Revelation Software web site: www.revelationprofits.com), I included the effect of weight.

The following table summarizes the result. It was possible to verify some of the numbers by comparing them, for example, with what Ainslie showed in his Encyclopedia of Thoroughbred Racing.

Note: The table when shown in this Forum may lose it's column structure and show on the screen without column spacing. I don't know how to correct this. The first column is race distance in furlongs, the second column is time change in ticks.

TABLE 1
Finish Time Change per One Pound Weight Change
Normalized to 116 pounds)

Race Distance Time Change
(Furlongs) (Ticks)
5 0.187
5.5 0.231
6 0.280
6.5 0.336
7 0.398
7.5 0.467
8 0.543
8.5 0.627
9 0.719
10 0.930
12 1.479
15 2.716
16 3.276

[Steve]

Thoroughbred,

It is always a pleasure to see one of your posts. Thanks for sharing. There are many who will appreciate this information and it's even better when the source is from an expert such as yourself.

Thanks Again,

Steve

[ken]

First, my belief is that like many other handicapping factors, wieght affecting the average horse can always be put into columns; but how much weight can any given TBred carri y to victory in any given race depends on at least a few variables, like wiehgt carried by certain competition, distance, track profile and speed.
My basic belief is that with most TBreds there is a certain amount of weight that can be carried successfully by a certain horse at a certain time in their development, as evidenced by the scale of weights. Also it is greatly dependent on the horse's size, stamina, fitness, and running style.
Generally I look to see maximum weight carried at a distance when finishing ITM.
I understand you did much research for this, but my question is-
you show 6.0 (6 furlongs) being 0.336 seconds, and 8.5 (1 1/16 mile) being 0.627 seconds (winner's time) for a difference of .291 seconds (by the old standard of 1 second = 5 lengths = 40', I get about 11.64' slower.
Should I use the same nubers for non- winners? And, can you give me an example of how I would compare say a 3 yr old vs a 4 yr old in a 3+up race if the 3 yr old is stretching out from 6f to 1 1/16 miles dirt, at what weights would the 2 horses be considered equal as far as carrying weight? Thanks!

[ken]

Hollywood 7-1 1st race, turf 1 1/8, has horses 4+ up; 1 stretched out last race, 2 bug weights, some ran 1 mile turf last out.
How would you deal with those weights?

[gestalt]

-the solution to the weight variable must be solved with the understanding of realism and instrumentalism. Refer to Dr. Eliot Sober and his paper on this subject matter. Real good stuff. Also look up Akaike's Theorum. Their material is good on predicitive ability. Bottom line is that weight is almost negligible in short sprints and becomes compounded in a 1 and 1/16 mile two turn dirt oval. For simplicity, i use 4# = .17 sec. or 8.80ft. at 7 furlongs. Any attempt to mix realism and instrumentalism is not logical. Fitted models must be used in the context of instrumentalism, any other use may or may not be true.

[FastG45]

:D I don't pay to much attention to weight if the race is a 1 mile or less. If one horse I like in a mile or less race is losing 10 or more pounds from his last race and another horse I like is gaining 10 or more pounds from his last race, that is a 20+ pound swing. If the two horses are close I will consider the lighter horse in my final decision. If they are pilling 140+ pounds on a horse in a sprint race I will take notice. In a route I look for 3+ pounds or more either way which makes a 6+ pound or more swing. In most circumstances no matter which way I go I'm wrong so who knows. ds:

[sace5326]

Thistledown
Favorite totes 148 and finishes last

By CHUCK SCARAVILLI
Most trainers try to find races in which their horses carry the least amount of weight. But in last Sunday's ninth race at Thistledown, trainer Burton Sipp entered Magoo's Magic for a $12,500 claiming tag and accepted 148 pounds.
The 4 1/2-furlong race had a base claiming price of $3,500, with older horses to carry 112 pounds. Trainers had the option of deciding what price their horse would run for but would receive an extra two pounds for each $500 in claiming price. In his previous start, Magoo's Magic was second at Mountaineer Park after setting the pace in a $15,000 claiming race for horses who had never won four races.

"I had entered the horse three times at Thistledown, but the races did not fill," said Sipp. "He is a very fast horse, and I have him valued at $12,500. I felt that if he caught a field of $3,500 and $5,000 horses, he could handle them despite the heavy package."

Sipp was not alone in his thinking. Bettors made Magoo's Magic, the stronger half of an entry, the 1-2 favorite in the field of seven. Magoo's Magic finished last, however, beaten 11 1/2 lengths. His stablemate, Soldier's Cutlass, finished fifth for a $6,500 claiming price under 124 pounds. No other horse was entered for more than a $5,000 claiming price. Anne Sanguinetti, who rode Magoo's Magic, tacks 112, which means Magoo's Magic carried 36 pounds of lead in his saddle pad.

Sanguinetti, who came from Suffolk Downs to ride first call on Sipp's 40 horses at Thistledown, rode Magoo's Magic, who is owned by Bridgette Sipp.

"It was an interesting experiment that didn't work out the way we wanted." Sanguinetti said. "I was curious as to what would transpire. I can't really say that the weight stopped him. He broke sharply, but before a quarter I knew he wasn't going to keep up and didn't abuse him the rest of the way."

Sipp's unorthodox decision to have Magoo's Magic carry so much weight, and spot his opposition from 24 to 36 pounds, is the latest oddity in his checkered career. Sipp, 62, was banned from racing for nine years, from 1984 to 1993, after he was indicted for fraud by a New Jersey grand jury for allegedly destroying horses for the purpose of collecting insurance claims. Sipp eventually pleaded guilty to witness tampering in the case and was sentenced to five years probation.

Since his return to racing, Sipp has been barred from a number of tracks, including River Downs in 1994 after he failed to disclose his prior suspension on his trainer's license application.

Sipp purchased Magoo's Magic from trainer Patrick Biancone at Turfway Park this winter and had started him four times before Sunday. Magoo's Magic brought $110,000 at the Keeneland September sale in 2003.

this was written 6-28-06
sounds to me this horse should have been in a steeple race with 148 lbs. on his back

scott

[thoroughbred]

Ken,

While the result came from the general math in the Engineering Report, the interpretation is straight forward.

The numbers tell us the difference in finish time that will result from a change in weight when COMPARED TO THE FINISH TIME of a previous race when the weight carried was different.

There is no part of it that takes into account other factors like maximum possible weight carried, and the like.

It is also important, when comparing the finish time with the new weight, to the finish time of a previous race with a different weight, to do our best to "even out the playing field", by adjusting for parameters such as track variant, for example.

Of course, continuing with the track variant as the example, the track variant for "today's" race is not available beforehand. So the way to handle this is to take the previous track variants of all the other horses into account from their previous races. Then, "today's" race, should have the correct weight adjustment for horse COMPARISONS, even though "today's" variant isn't known. In other words, for this one variable, i.e., track variant the horses have been "equalized."

One thing along these lines that has proven to be useful, is that BRIS and TSN, normalize their speed ratings over all the tracks. So when a variant is calculated from such a speed variant, (as is done, by the way, in Computrak), the adjustments for track pars and variants of the various tracks on which the horses may have raced. is included in the finish time calculation.

[ken]

Ok, that tells me there is a certain averaging that lends validity to the stats!

[gestalt]

Ok, that tells me there is a certain averaging that lends validity to the stats!Which may or may not be true.

[gestalt]

One set of formulas widely accepted, many whom concede it the authority of Holy Writ.
1. Four extra pounds of weight slows a horse by 1/5 sec., or one full length, in a sprint.
2. Three extra pounds have the same effect at a mile.
3. Two extra pounds have the same effect at a 1 1/8 mile.
4. One extra pound has the same effect at a 1 1/4 mile.
Ainslie said it may be so, but nobody can prove it, well you have proved it. Your data becomes very powerful when used in anaerobic state.

[Jerfi]

Weight is something I do NOT look at, at all. It may make some difference, some of the time, to be sure, but my own stat analysis, over the last 25 years, indicates that it is a non-vital factor in handicapping.

Yes, I know anyone can show me race after race after race where the winner carries less weight.... but I can show anyone just as many where an increase in weight is still carried by the winner.

My rationale is that there are so many factors in handicapping, that one cannot possibly consider them all, in relation to all the other factors, and somehow, somewhere, some way, one must rank his factors.

What, for example, would you do with a maiden who is 0 for 30 in MSW races, dropping to bottom claimers, carrying 107 pounds? Is it an automatic bet for $2, or do you put a serious wager on it? Now, I now that you have already thought of several questions you want to ask? Who's the jock? Who's the trainer? What's his speed rating? ad infinitum.

The winner of any race is determined by a wide range of factors, weight being only one ...and ... in my opinion and experience, one of the very lesser factors!